APUSH WARS

US Revolutionary War

(1775–1783)

• Why it matters: Independence from Britain, birth of American political identity.

• Must-know: Leads to Declaration of Independence (1776) and Treaty of Paris (1783).

🔑 Key idea: War for liberty and national identity.

⚓ War of 1812

• Why it matters: U.S. reasserts independence from Britain, boosts nationalism.

• Must-know: U.S. fights Britain again; ends in stalemate but leads to the Era of Good Feelings.

🔑 Key idea: Nationalism rises, Federalist Party dies.

🧭 Mexican-American War

(1846–1848)

Why it matters: U.S. gains the Mexican Cession

• California 🌴

• Nevada

• Utah

• Most of Arizona

• Parts of New Mexico

• Parts of Colorado

• Parts of Wyoming

🧠 This doubled down on Manifest Destiny — the belief that the U.S. was destined to stretch “from sea to shining sea.”(huge land, including California).

• Must-know: Treaty of Guadalupe Hidalgo, reignites slavery debate over new territories.

🔑 Key idea: Expansion → Tension over slavery explodes.

⚔ Civil War

(1861–1865)

• Why it matters: Union vs. Confederacy over slavery and secession.

• Must-know: Emancipation Proclamation (1863), Union wins, slavery abolished.

🔑 Key idea: War that redefined freedom and preserved the Union.

🌍 Spanish-American War

(1898)

• Why it matters: U.S. becomes an imperial power.

• Must-know: Gains Puerto Rico, Guam, Philippines; annexes Hawaii; “splendid little war.”

🔑 Key idea: U.S. starts acting like a world empire.

🌎 World War I

(1917–1918 for U.S.)

• Why it matters: U.S. joins late, helps win; sets up interwar tensions.

• Must-know: Wilson’s 14 Points, U.S. doesn’t join League of Nations.

🔑 Key idea: U.S. wants peace, but chooses isolationism after.

🌐 World War II

(1941–1945)

• Why it matters: Total war mobilization; U.S. becomes global superpower.

• Must-know: Pearl Harbor, D-Day, Hiroshima/Nagasaki, internment of Japanese Americans.

🔑 Key idea: Ends Great Depression, starts Cold War era.

❄ Cold War Conflicts

(Not one war, but a series of proxy wars)

• Key conflicts:

  • Korean War (1950–1953) – first U.N. war; ends in stalemate.

  • Vietnam War (1955–1975) – long, controversial; ends in U.S. withdrawal.

• Why it matters: U.S. vs. Soviet Union ideological battle (capitalism vs. communism).

🔑 Key idea: U.S. tries to contain communism worldwide.

TRUMAN DOCTRINE (1947): A U.S. foreign policy promising to support any country fighting communism — mostly through military and economic aid.
MARSHALL PLAN (1948): A massive economic aid program to rebuild Western Europe after WWII — so countries wouldn’t turn to communism out of desperation.