The Democratic Party platform of 1856 explicitly supported the expansion of slavery into territories acquired from Mexico during the Mexican-American War.

The Republican Party platform of 1860 unequivocally demanded the abolition of slavery in all territories, setting the stage for the Civil War.

The Compromise of 1850 was a series of legislative measures designed to appease both pro-slavery and anti-slavery factions and prevent the dissolution of the Union.

The Missouri Compromise of 1820 drew a line at 36°30' North latitude, prohibiting slavery in territories north of that line.

The Kansas-Nebraska Act of 1854 overturned the Missouri Compromise, allowing for the expansion of slavery into territories previously designated as free.

The Wilmot Proviso aimed to ban slavery in all territories acquired from Mexico during the Mexican-American War.

The Dred Scott decision exacerbated tensions between the North and South, contributing to the outbreak of the Civil War.

The Republican Party platform of 1864 unequivocally demanded the abolition of slavery throughout the United States.

Abraham Lincoln was the president when the Thirteenth Amendment was ratified, fulfilling his Emancipation Proclamation.

Andrew Johnson was the president when the Fourteenth Amendment was ratified, extending citizenship to all persons born or naturalized in the United States.

Ulysses S. Grant was the president when the Fifteenth Amendment was ratified, securing the right to vote for African Americans.

The Compromise of 1877 settled the electoral dispute between Rutherford B. Hayes and Samuel J. Tilden, averting a potential constitutional crisis.

The Populist Party platform called for a range of progressive policies, including government ownership of railroads and utilities, bimetallism, graduated income tax, and direct election of senators.

Theodore Roosevelt, a former Republican president, led the Progressive Party in 1912, advocating for progressive reforms and social justice.

The New Deal encompassed a wide range of policies designed to stimulate economic recovery, provide social welfare programs, and reform the financial system.