## Learning Outcomes

- Identify the main arguments Americans used to support overseas expansion after **1890**
- Explain how economic, strategic, ideological, and nationalist motives worked together
- Recall key figures and evidence, including **Alfred Thayer Mahan**, **Josiah Strong**, **Albert J. Beveridge**, and **John Hay**
- Distinguish between causes of the **Spanish-American War** and broader arguments for empire
- Explain why **1898** was a turning point in U.S. foreign policy
- Use specific evidence about **Hawaii**, the **Philippines**, **China**, and **Cuba** in SAQ, DBQ, and LEQ answers

## AP United States History Syllabus

For the AP United States History, you are expected to understand imperialist arguments for expansion in the late 19th and early 20th centuries, with a focus on the following syllabus points:

- Know that pro-expansion arguments after **1890** usually fell into economic, strategic, ideological, and nationalist categories
- Identify the importance of **Alfred Thayer Mahan** and _The Influence of Sea Power upon History_ (**1890**)
- Explain how the closing of the frontier and **Frederick Jackson Turner’s Frontier Thesis** (**1893**) shaped arguments for a “new frontier” overseas
- Understand how **Josiah Strong**, Social Darwinism, and the “civilizing mission” justified imperialism
- Recognise **1898** as a key turning point, especially through the **Spanish-American War**, annexation of **Hawaii**, and the **Treaty of Paris (1898)**
- Distinguish between formal empire in the **Philippines, Puerto Rico, and Guam** and informal influence in **Cuba** and **China**
- Explain the purpose of the **Open Door Notes (1899–1900)** and the difference between trade access and annexation
- Understand how the **Teller Amendment**, **Platt Amendment**, and **Insular Cases** exposed tensions between republican ideals and imperial practice

## Test Your Knowledge

_Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, look more closely at that area during your revision._

1. What were the four main types of argument used by American imperialists after 1890?
2. How did **Alfred Thayer Mahan** connect naval power to overseas expansion?
3. Why is **1898** usually treated as a turning point in U.S. foreign policy?
4. What is the difference between the **Teller Amendment** and the **Platt Amendment**?
5. How did arguments about “civilization” differ from arguments about markets and trade?

## Introduction

In APUSH Unit 7, imperialism is not just about what the United States did overseas. It is also about how Americans justified doing it. Exam questions often ask why expansion happened, what ideas supported it, and how those ideas fit into bigger themes such as **America in the World** and **Politics and Power**.

The strongest way to revise this topic is to group pro-imperialist arguments into four categories: economic, strategic, ideological, and nationalist. That structure helps in multiple-choice questions and gives you an instant essay plan.

> **Key Term: imperialism**
> A policy in which a nation extends its political, military, or economic influence over other territories or peoples.

### Economic arguments: markets, trade, and the search for opportunity

By the late 19th century, the United States had become a major industrial economy. Factories could produce huge amounts of steel, machinery, textiles, and consumer goods. That success created a problem as well as an advantage: American businesses feared overproduction. If U.S. factories produced more than Americans could buy, profits could fall.

Imperialists argued that expansion would solve this by opening **overseas markets**. New territories and new trade relationships would give American producers more customers. This argument became especially strong after the depression of the **1890s**, when many Americans worried about instability at home and wanted growth abroad.

> **Key Term: overseas markets**
> Foreign regions where American businesses could sell goods, invest money, and gain access to trade opportunities.

Supporters of expansion did not always want direct conquest. Sometimes they wanted influence without annexation. That is why **China** matters so much in this topic. The United States feared that European powers and Japan would divide China into exclusive spheres of influence and shut Americans out. Secretary of State **John Hay** responded with the **Open Door Notes** in **1899** and **1900**, asking major powers to keep Chinese trade open to all.

> **Key Term: Open Door Policy**
> A U.S. policy seeking equal commercial access to China for all powers, rather than exclusive colonial control by one nation.

This is a common exam distinction: imperialism could be **formal**, through direct control of territory, or **informal**, through trade pressure and diplomatic influence. The Open Door Policy shows informal imperialism. The Philippines shows formal imperialism.

**Albert J. Beveridge** is one of the best examples of the economic argument. In his **1898** speech “The March of the Flag,” he defended keeping the Philippines not just as islands, but as a route to “China’s...markets.” His logic was clear: the Philippines would help the United States project power into Asia and profit from Asian commerce.

Students often make a mistake here by treating economics as the only cause. It was important, but not sufficient by itself. Markets mattered because policymakers also thought in military and cultural terms.

> **Test Tip:** In an LEQ or SAQ, do not just say “the U.S. wanted money.” Be more specific: write about industrial overproduction, the search for overseas markets, access to China, and investment opportunities.

### Strategic arguments: sea power, bases, and control of key routes

Economic expansion needed protection. That is where strategic thinking came in. The most important name here is **Alfred Thayer Mahan**, whose book _The Influence of Sea Power upon History_ appeared in **1890**.

Mahan argued that great nations needed a strong modern navy. But a navy could not operate globally without support. Steam-powered ships needed fuel, repairs, and protected harbours. So naval strength required a chain of **coaling stations**, island bases, and ports across the world.

> **Key Term: sea power**
> The idea that national strength depends heavily on naval force, commercial shipping, and access to overseas bases.
>
> **Key Term: coaling station**
> An overseas refuelling point used by steam-powered naval and merchant ships.

This argument helps explain why **Hawaii** became so important. American missionaries and sugar planters had long been active there, but annexation in **1898** was justified partly in strategic terms. **Pearl Harbor** offered the United States a vital Pacific naval base. Hawaii was not just profitable; it was positioned between the U.S. mainland and Asia.

The same logic shaped interest in a canal across Central America. A canal would cut travel time between the Atlantic and Pacific and allow the navy to move quickly between oceans. That is why later policy in **Panama** fit imperial strategy so well. Even though the canal opened in **1914**, the argument for it developed in the earlier imperial period.

The strategic argument also helps explain why expansionists defended the **Philippines**. Holding the islands meant influence in the western Pacific and a forward base close to Asian trade routes.

A useful comparison for exams is this:

- **Economic argument:** we need markets abroad
- **Strategic argument:** we need ships, bases, and routes to reach and defend those markets

They are linked, but not identical.

**Henry Cabot Lodge** also supported imperial expansion for strategic reasons. He wanted the United States to compete with European empires and avoid falling behind in world politics. In his view, a major power that lacked a navy and overseas bases would become weak.

> **Test Tip:** If a source mentions fleets, harbours, canals, naval bases, or Pacific islands, think strategic argument before economic argument, even if both are present.

### Ideological arguments: civilization, religion, and racial hierarchy

Some imperialists said expansion would help American business. Others said it would help supposedly “backward” peoples. This was the paternalistic side of imperialism.

**Josiah Strong**, in _Our Country_ (**1885**), promoted the belief that Anglo-Saxon Protestants had a duty to spread Christianity and “civilization.” This was not the same as pure missionary work. It mixed religion with racial hierarchy and national self-confidence.

> **Key Term: Social Darwinism**
> The misuse of evolutionary ideas to argue that stronger nations or races were naturally entitled to dominate weaker ones.

Social Darwinism gave imperialists a language of “fitness” and “progress.” Some Americans claimed that nations, like organisms, struggled for survival. Strong nations expanded; weak ones declined. This made empire seem natural and even necessary.

At the same time, imperialists often framed conquest as a moral duty. The phrase **“white man’s burden”**, popularised by **Rudyard Kipling** in **1899**, captured the belief that white, Western powers should rule nonwhite peoples for their own supposed benefit. In practice, this argument rested on condescension and racism.

The **Philippines** became the clearest case. Expansionists claimed Filipinos were not ready for self-government and needed American supervision. Beveridge blended this with religious and racial language, arguing that history and Providence had prepared Anglo-Saxon peoples for rule.

This is where APUSH rewards precision. Do not treat all ideological arguments as the same thing.

- **Missionary argument:** spread Christianity and moral uplift
- **Social Darwinist argument:** stronger peoples naturally dominate weaker ones
- **Civilizing mission:** U.S. rule would supposedly bring order, education, and progress

These overlap, but they are not identical.

There was also a contradiction here that good essays should point out. Americans celebrated republican self-government at home while denying that same right to others abroad. Anti-imperialists attacked exactly this contradiction, but even pro-imperialists often hid it behind language about tutelage and preparation.

### Nationalist arguments: prestige, frontier anxiety, and the world-power mindset

By the **1890s**, many Americans thought a great nation should act like a great power. European states had empires. Japan was rising. Supporters of expansion argued that if the United States wanted international respect, it needed a global presence too.

> **Key Term: jingoism**
> Aggressive nationalism that strongly supports war and expansion.

This argument became stronger after the **1890 census** declared the frontier effectively closed. For decades, continental expansion had given Americans land, movement, and a sense of mission. Once the western frontier seemed finished, some expansionists looked overseas for a “new frontier.”

This is where **Frederick Jackson Turner’s Frontier Thesis** (**1893**) matters. Turner himself was explaining the historical importance of the frontier, not directly demanding empire. But others adapted his idea. If the frontier had shaped American energy and democracy, then overseas expansion might continue that process.

> **Key Term: Frontier Thesis**
> Frederick Jackson Turner’s argument that the American frontier shaped national character and democracy.

National prestige also mattered in war. The **Spanish-American War** in **1898** is often confused with the arguments for empire. Keep the distinction clear. Immediate causes of war included Cuban revolt, yellow journalism, the **De Lôme Letter**, and the explosion of the **USS Maine**. But the deeper pro-imperialist mindset meant that once war began, many Americans were ready to keep the territories won from Spain.

The **Treaty of Paris (1898)** marked the turning point. Spain ceded **Puerto Rico**, **Guam**, and the **Philippines** to the United States. Cuba was not annexed, but American influence remained strong.

> **Key Term: Treaty of Paris (1898)**
> The treaty ending the Spanish-American War, under which Spain ceded Puerto Rico, Guam, and the Philippines to the United States.

Cuba shows another major distinction students must know. The **Teller Amendment** promised that the U.S. would not annex Cuba. That sounded anti-colonial. But the later **Platt Amendment** (**1901**) limited Cuban sovereignty and gave the U.S. the right to intervene, while also securing **Guantánamo Bay**. So even where the U.S. denied seeking formal empire, it often built informal empire.

> **Key Term: Teller Amendment**
> An 1898 declaration that the United States would not annex Cuba after the war with Spain.
>
> **Key Term: Platt Amendment**
> A 1901 measure limiting Cuban independence and allowing U.S. intervention in Cuban affairs.

Finally, the **Insular Cases**, especially **Downes v. Bidwell** (**1901**), showed the constitutional consequences of empire. The Supreme Court ruled that full constitutional rights did not automatically extend to all U.S. territories. That made imperial rule easier, because Congress could govern conquered peoples without granting full equality.

> **Key Term: Insular Cases**
> Supreme Court decisions holding that full constitutional rights did not automatically apply in all U.S. territories.

## Key Point Checklist

_This article has covered the following key knowledge points:_

- Imperialist arguments after 1890 can be grouped into economic, strategic, ideological, and nationalist categories
- Economic arguments stressed overseas markets, investment, and access to trade, especially in China
- The Open Door Policy aimed to secure trade access in China without direct annexation
- Alfred Thayer Mahan argued in 1890 that national greatness required sea power, a strong navy, and overseas bases
- Hawaii mattered to expansionists because of Pearl Harbor and its position on the route to Asia
- Strategic arguments for empire also supported the need for a canal across Central America
- Josiah Strong and Social Darwinist ideas helped justify expansion through missionary and racial language
- The “white man’s burden” described a paternalistic and racist claim that Americans should rule other peoples for their own good
- The closing of the frontier after 1890 encouraged some Americans to think in terms of a new overseas frontier
- 1898 was a turning point because the Spanish-American War and Treaty of Paris produced a formal overseas empire
- The Teller Amendment promised Cuban independence, while the Platt Amendment later limited that independence
- The Insular Cases showed that empire created major constitutional tensions over rights in U.S. territories

## Key Terms and Concepts

- imperialism
- overseas markets
- Open Door Policy
- sea power
- coaling station
- Social Darwinism
- jingoism
- Frontier Thesis
- Treaty of Paris (1898)
- Teller Amendment
- Platt Amendment
- Insular Cases


Imperialism: Debates - Imperialist arguments for expansion