The “Five Civilized Tribes” were the Cherokee, Seminole, Choctaw, Creek, and Chickasaw. They were so-called by European settlers and the citizens of the early American republic because they were willing to adopt European customs and maintained generally peaceful relations with the settlers. The Lakota tribe resided in what is now modern day North and South Dakota and throughout the nineteenth century fought occasional conflicts with the United States Army. 

The Trail of Tears is the name usually given to the forced relocation of several Native American populations from the Southeastern United States to what is now Oklahoma. It followed the passage of the Indian Removal Act of 1830, during the Presidency of Andrew Jackson. Many Native Americans suffered from disease and starvation during the trail, hence the name “Trail of Tears.”

Andrew Carnegie was a Scottish immigrant who arrived in America in 1848 and built one of the largest companies of the nineteenth century. He sold the Carnegie Steel Company to J.P. Morgan at the turn of the century and retired to a life of philanthropy. In his article Gospel of Wealth, Carnegie argues that it is the duty of the newly-made wealthy industrial class to redistribute their riches back to the poor. Carnegie focused his energy on educational institutions—particularly schools, libraries, research centers, and universities. 

In 1854, the Kansas-Nebraska Act became law and decreed that the residents of the Kansas and Nebraska Territories could vote whether to enter the Union as free or slave states. In the immediate aftermath of the bill, large groups of both pro-slavery and anti-slavery settlers moved to the Kansas Territory. For the next 6 years, Kansas saw a variety of violent conflicts and political maneuvers over the issue. Eventually, Kansas entered the Union as a free state in January of 1861, three months before the Civil War started at Fort Sumter.

The doubling of the U.S. population from 1790 to 1820 was primarily the result of reproduction. It was not until after the early 1820s that immigration numbers began to dramatically increase.

During the 19th century, the Germans and the Irish were the largest immigrant populations in the United States. The Irish Potato Famine during the 1840s led to an increase in the already high Irish immigration numbers, and the 1848 revolutions in Germany led to an even greater increase in the already higher German immigration numbers. From 1840-1880 Germany supplied the greatest number of immigrants to the United States.

All four of these were social reform movements that began in the period before the American Civil War. Other reforms during the antebellum period include prison reforms, mental hospital reforms, education reforms, Protestant revivalism, and more.

The quote refers to the difficulty of American men to reintegrate into society following World War I. The majority of Americans in that era had never been more than a few hundred miles from their homes, let alone across continents. In addition, many men suffered from extreme trauma from the events they witnessed and participated in. A lot of jobs had been taken up by women, in the absence of male workers, and post-war society faced the problem of how to resolve this disparity.

The Eighteenth Amendment was the culmination of a decades long temperance movement that sought to end all alcohol sales, distribution, and consumption in America.  Initially celebrated as a progressive victory, the legal enforcement of prohibition proved a nightmare, and legions of criminal gangs began to control the illegal alcohol sales.  The Eighteenth Amendment was repealed by the Twenty First Amendment in 1933.

In Brown, Chief Justice Earl Warren expressed that in the arena of public education, "separate but equal" is inherently unequal, unfair, and unconstitutional. Plessy v. Ferguson is a prior case that upheld the "separate but equal" doctrine.