The Price of Freedom: Americans at War
This Smithsonian website skillfully integrates Flash video and text to examine armed conflicts involving the U.S. from the Revolutionary War to the war in Iraq.
The Civil War by 
D-Day and the Normandy Campaign by 
American Heroes by 
The United States at War by 
The American Revolution by 
Thomas Jefferson and the Tripoli Pirates by 
Andrew Jackson and the Miracle of New Orleans by 
A Short History of the Second World War by 
The Korean War by 
First World War for Dummies by FRENCH AND INDIAN WAR (1756–1763)
THE REVOLUTIONARY WAR (1775-1783)
WAR OF 1812 (1812-1815)
MEXICAN - AMERICAN WAR (1846-1848)
AMERICAN CIVIL WAR (1861–1865)
SPANISH-AMERICAN WAR (1898)
WORLD WAR I (1914-1918)
WORLD WAR II (1939-1945)
KOREAN WAR (1950-1953)
VIETNAM WAR (1959-1975)
BAY OF PIGS INVASION (1961)
GULF WAR (1990-1991)
WAR IN AFGHANISTAN (2001-PRESENT)
INVASION OF IRAQ ( 2003 - 2011)
U.S.-LED INTERVENTION IN IRAQ (2014–2017)
U.S.-LED INTERVENTION IN SYRIA (2014–present)
YEMENI CIVIL WAR (2015–present)
U.S.-LED INTERVENTION IN LIBYA (2015–present)
The Coast Guard Historian's Office
History of the Coast Guard
The American Battle Monuments Commission
established by Congress in 1923, is an agency of the executive branch of the federal government. ABMC — guardian of America’s overseas commemorative cemeteries and memorials — honors the service, achievements and sacrifice of U.S. Armed Forces.
Vietnam Center at Texas Tech University
the Vietnam Center at Texas Tech University is to support and encourage research and education regarding all aspects of the American Vietnam experience; promoting a greater understanding of this experience and the peoples and cultures of Southeast Asia.
Naval History and Heritage Command
History of the Navy
The Air Force Historical Research Agency
The repository for Air Force historical documents
MILITARY HISTORY
Lion Heart filmworks youtube channel
Videos on history of the military and wars involving the united states
Information on the various wars and battles
U.S. Army Center of Military History
The dramatic documentary tells the story of the French and Indian War (1754-1763), which began in the wilderness of the Pennsylvania frontier and spread throughout the colonies, into Canada, and ultimately around the world
HIST 119 - The Civil War and Reconstruction Era, 1845-1877
course from Yale University that explores the causes, course, and consequences of the American Civil War, from the 1840s to 1877.
THE ORIGINS OF THE COLD WAR: 1945 - 1955
Cold War History and origins
Links to military reference material, military history and research, and to specific topics.
United States Military Academy Westpoint: HistoryAtlases
Atlases
The Revolution - History Channel
Video playlist from the history channel on the American Revolution
World War II Full Documentary Series