Got milk? Only two cultures have had it long enough to develop the tolerance of lactose as an adult. Learn how the responsible genes evolved along with the cultures that have been consuming milk. This rich film is supplied with a few...

This video lesson from Khan Academy covers Period 7: 1890-1945 in American History. The sinking of the Lusitania, and its connection to President Woodrow Wilson's declaration of war is discussed in this lesson. This resource is designed...

This video lesson from Khan Academy covers Period 7: 1890-1945 in American History. Social activism, particularly the Progressive Reform Movement, is discussed. This resource is designed as a review for the AP US History Test.

This video lesson from Khan Academy covers Period 7: 1890-1945 in American History. The Paris Peace Conference and Treaty of Versailles are discussed. This resource is designed as a review for the AP US History Test.

This video lesson from Khan Academy covers Period 6: 1865-1898 in American History. Continuity and change, as it pertains to the Gilded Age, are discussed. This resource is designed as a review for the AP US History Test.

This video lesson from Khan Academy covers Period 7: 1890-1945 in American History. The debates surrounding America's transformation into an imperialist country are discussed. This resource is designed as a review for the AP US History...

This video lesson from Khan Academy covers Period 6: 1865-1898 in American History. Reform in the Gilded Age is discussed, specifically associated with poverty and women's rights. This resource is designed as a review for the AP US...

This video lesson from Khan Academy covers Period 6: 1865-1898 in American History. The historical perspectives of Social Darwinism, as it pertains to evolution, are discussed. This resource is designed as a review for the AP US History...

Meet Kim - one of the creators of Khan Academy's AP US History lessons. Kim earned her Ph.D. in history at the University of North Carolina at Chapel Hill and taught US history at the college level for eight years. She has graded the AP...

This Khan Academy resource provides a video lesson [6:19] that provides a plot summary and analysis of the book Uncle Tom's Cabin. This lesson emphasizes the impact of this book on American readers. The lesson is accompanied with a...

The Civil War is often considered the most transformative event in US history. But how much did it really change American national identity? In this video, Kim compares the relative significance of the effects of the Civil War on...

How did events in the years after 1980 affect national identity in the United States? Kim discusses changes in US foreign policy, economics, and politics, attempting to place the developments of this era into a broader historical...

Kim compares the effect of major developments like the Great Depression and World II on American core beliefs about individualism, culture, and the proper US role in the world. [8:31]

By the 1920s, a majority of the US population lived in cities rather than in rural areas. Kim explores the economic opportunities cities offered to women, migrants, and immigrants, as well as the passage of new immigration restrictions....

What were the causes and effects of the Mexican-American War? In this video, Kim discusses how Manifest Destiny and the annexation of Texas brought on the war, as well as how the war affected US politics and the existing residents of the...

In 1820, James Monroe articulated the US foreign policy goal of ending European colonization in the Americas. [14:32]

What changed- and what stayed the same- with the growth of industrial capitalism in the United States during the Gilded Age? In this video, Kim discusses how technological innovation, business innovation, and pro-growth government...

1945 marks the end of World War II. V-E Day (Victory in Europe Day) is May 8th 1945. War doesn't end in the Pacific until August of 1945 with the atomic bombing of Hiroshima and Nagasaki. [8:03]

As we go into 1944, we see the allies land at Normandy, liberate France and face Germany in their last major counteroffensive at the Battle of the Bulge. On the Eastern Front, the Soviets end Siege of Leningrad and begin to push through...

In 1944, the Americans (and Allies) make even more progress in the Pacific. By the end of the year, they have taken positions that put them within bombing range of Japan. [7:34]

In 1943, the tide really turns in favor of the Allies in World War II. They are able to push the Axis out of N.Africa and force a surrender from Italy (along with Mussolini being deposed). The Soviets are able to start pushing the Axis...

In 1942, the United States begins to fully engage against the Japanese and go on the offensive. [5:50]

In 1942 we see the Axis get pushed back in North Africa and get bogged down in the Soviet Union. The tide of war turns in favor of the Allies. [5:11]