Act of 1862 parceled out millions of acres of land to settlers. All US citizens, including women, African Americans, freed slaves, and immigrants, were eligible to apply to the federal government for a "homestead," or 160-acre plot of land.
Homesteading was a contentious issue, because Northerners and Republicans wanted to open the land to settlement by individual farmers, while Southern Democrats sought to make the land available only to slaveholders.
The exodusters were African American migrants who left the South after the Civil War to settle in the states of Colorado, Kansas, and Oklahoma.
In the nineteenth century, Mexican American, Chinese, and white populations of the United States collided as white people moved farther west in search of land and riches.
Neither Chinese immigrants nor Mexican Americans could withstand the assault on their rights by the tide of white settlers. Ultimately, both ethnic groups retreated into urban enclaves, where their language and traditions could survive.
Las Gorras Blancas, the White Caps, were a rebel group of Mexican Americans who fought back against the appropriation of their land by white settlers; in 1889 and 1890, they burned farms, homes, and crops.
On the morning of December 7, 1941, Japan attacked the US naval base at Pearl Harbor, Hawaii.
The surprise attack by some 350 Japanese aircraft sunk or badly damaged eighteen US naval vessels, including eight battleships, destroyed or damaged 300 US aircraft, and killed 2,403 men.
Across the nation, Americans were stunned, shocked, and angered. The attack turned US public opinion in favor of entering the Second World War. The United States declared war on Japan on December 8, 1941.
Japan's allies, Germany and Italy, declared war on the United States on December 11. The United States responded in kind, and therefore entered World War II.
On December 1, 1955, Rosa Parks, a black seamstress, was arrested in Montgomery, Alabama for refusing to give up her bus seat so that white passengers could make use of it.
Rosa Parks's arrest sparked Boycott, during which the black citizens of Montgomery refused to ride the city's buses in protest over the bus system's policy of racial segregation. It was the first mass-action of the modern civil rights era, and served as an inspiration to other civil rights activists across the nation.
Martin Luther King, Jr., a Baptist minister who endorsed nonviolent civil disobedience, emerged as leader of the Boycott.
Following a November 1956 ruling by the Supreme Court that segregation on public buses was unconstitutional, the bus boycott ended successfully. It had lasted 381 days.
In the late 1960s and 1970s, Native Americans, gay men, lesbians, and women organized to change discriminatory laws and pursue government support for their interests, a strategy known as identity politics.
These groups, whose aims and tactics posed a challenge to the existing state of affairs, often met with hostility from individuals, local officials, and the US government.
Identity politics are political movements or actions intended to further the interests of a particular group, based on culture, race, ethnicity, religion, sex, gender, or sexual orientation.
The disease AIDS (acquired immunodeficiency syndrome) first appeared in the early 1980s, and rapidly became an epidemic among homosexual men. Intravenous drug users who shared needles, blood transfusion patients, and women with infected sexual partners were also at risk of contracting AIDS.
Activists, particularly in the gay community, responded by creating care and education centers, and by calling for increased government funding to help in the crisis. Though the US government at first did little to respond to the crisis, it eventually committed millions of dollars to research, care, and public education.
Fear of contracting the disease and discrimination against those with AIDS persisted throughout the 1980s and 1990s, even though the US Centers for Disease Control and Prevention (CDC) ruled out the possibility of transmitting AIDS through casual contact in 1983.
AIDS deaths increased throughout the decade. In 1986, 12,000 Americans died of AIDS. By 1988, that figure had grown to 20,000. AIDS also proved deadly in Africa and elsewhere in the world.