Slave states and free states in the context of "Dred Scott decision"

The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclave of Alaska in the northwest and the archipelago of Hawaii in the Pacific Ocean. The United States also asserts sovereignty over five major island territories and various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's third-largest land area and third-largest population, exceeding 340 million.

Paleo-Indians first migrated from North Asia to North America over 12,000 years ago, and formed various civilizations. Spanish colonization established Spanish Florida in 1513, the first European colony in what is now the continental United States. British colonization followed with the 1607 settlement of Virginia, the first of the Thirteen Colonies. Enslavement of Africans was practiced in all colonies by 1770 and supplied most of the labor for the Southern Colonies' plantation economy. Clashes with the British Crown over taxation and lack of parliamentary representation sparked the American Revolution, leading to the Declaration of Independence on July 4, 1776. Victory in the 1775–1783 Revolutionary War brought international recognition of U.S. sovereignty and fueled westward expansion, dispossessing native inhabitants. As more states were admitted, a North–South division over slavery led the Confederate States of America to attempt secession and fight the Union in the 1861–1865 American Civil War. With the United States' victory and reunification, slavery was abolished nationally. By 1900, the country had established itself as a great power, a status solidified after its involvement in World War I. Following Japan's attack on Pearl Harbor in 1941, the U.S. entered World War II. Its aftermath left the U.S. and the Soviet Union as rival superpowers, competing for ideological dominance and international influence during the Cold War. The Soviet Union's collapse in 1991 ended the Cold War, leaving the U.S. as the world's sole superpower.

The Union is a term used to refer to the central government and loyal states of the United States during the American Civil War. Its military forces and civilian population resisted the purported secession of the slave states that formed the Confederate States of America following the 1860 election of Abraham Lincoln as president of the United States. Lincoln's administration asserted the permanency of the federal government and the continuity of the United States Constitution, and it refused to recognize the Confederate government.

Nineteenth-century Americans commonly used the term Union to mean either the federal government of the United States or the unity of the states within the federal constitutional framework. The Union can also refer to the people or territory of the states that remained loyal to the national government during the war. The loyal U.S states located mostly above the Mason–Dixon line were also known as the North, although four southern border states and the future state of West Virginia remained loyal to the Union, and Black Southerners and many Southern Unionists opposed secession and supported the Union war effort.

California (/ˌkælɪˈfɔːrniə/) is a state in the Western United States that lies on the Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares an international border with the Mexican state of Baja California to the south. With almost 40 million residents across an area of 163,696 square miles (423,970 km), it is the largest state by population, third-largest state by area and the largest state economy in the U.S., with a GDP of approximately $4.1 trillion.

Prior to European colonization, California was one of the most culturally and linguistically diverse areas in pre-Columbian North America. European exploration in the 16th and 17th centuries led to the colonization by the Spanish Empire. The area became a part of Mexico in 1821, as a result of its successful war for independence. Following the U.S. conquest of California, part of the Mexican-American War, California was ceded to the United States in 1848. The California gold rush started in 1848 and led to social and demographic changes, including the California genocide. It organized itself and was admitted as the 31st state in 1850 as a free state, following the Compromise of 1850.

Ohio (/oʊˈhaɪ.oʊ/ oh-HY-oh) is a state in the Midwestern region of the United States. It borders Lake Erie to the north, Pennsylvania to the east, West Virginia to the southeast, Kentucky to the southwest, Indiana to the west, and Michigan to the northwest. Of the 50 U.S. states, it is the 34th-largest by area. With a population of nearly 11.9 million, Ohio is the seventh-most populous and tenth-most densely populated state. Its capital and most populous city is Columbus, with other major metropolitan centers including Cleveland and Cincinnati, as well as Dayton, Akron, and Toledo. Ohio is nicknamed the "Buckeye State" after its Ohio buckeye trees, and Ohioans are also known as "Buckeyes".

Ohio derives its name from the Ohio River that forms its southern border, which, in turn, originated from the Seneca word ohiːyo', meaning "good river", "great river", or "large creek". The state was home to several ancient indigenous civilizations, with humans present as early as 10,000 BC. It arose from the lands west of the Appalachian Mountains that were contested by various native tribes and European colonists from the 17th century through the Northwest Indian Wars of the late 18th century. Ohio was partitioned from the Northwest Territory, the first frontier of the new United States, becoming the 17th state admitted to the Union on March 1, 1803, and the first under the Northwest Ordinance. It was the first post-colonial free state admitted to the union and became one of the earliest and most influential industrial powerhouses during the 20th century.

South Carolina (/ˌkærəˈlaɪnə/ KARR-ə-LY-nə) is a state in the Southeastern, South Atlantic and Deep South regions of the United States. It borders North Carolina to the north and northeast, the Atlantic Ocean to the southeast, and Georgia to the west and south across the Savannah River. Along with North Carolina, it makes up the Carolinas region of the East Coast. South Carolina is the 11th-smallest and 23rd-most populous U.S. state with a recorded population of 5,118,425 according to the 2020 census. In 2019, its GDP was $213.45 billion. South Carolina is composed of 46 counties. The capital is Columbia with a population of 136,632 in 2020; while its most populous city is Charleston with a 2020 population of 150,227. The Greenville-Spartanburg-Anderson, SC Combined Statistical Area is the most populous combined metropolitan area in the state, with an estimated 2023 population of 1,590,636.

South Carolina was named in honor of King Charles I of England, who first formed the English colony, with Carolus being Latin for "Charles". In 1712 the Province of South Carolina was formed. One of the original Thirteen Colonies, South Carolina became a royal colony in 1719. During the American Revolutionary War, South Carolina was the site of major activity among the American colonies, with more than 200 battles and skirmishes fought within the state. South Carolina became the eighth state to ratify the U.S. Constitution on May 23, 1788. A slave state, it was the first state to vote in favor of secession from the Union on December 20, 1860. After the Civil War ended, the state was readmitted to the Union on July 9, 1868.

Kansas (/ˈkænzəs/ KAN-zəss) is a landlocked state in the Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named after the Kansas River, in turn named after the Kansa people. Its capital is Topeka, and its most populous city is Wichita; however, the largest urban area is the bi-state Kansas City metropolitan area split between Kansas and Missouri.

For thousands of years, what is now known as Kansas was home to numerous and diverse Indigenous tribes. The first settlement of non-indigenous people in Kansas occurred in 1827 at Fort Leavenworth. The pace of settlement accelerated in the 1850s, in the midst of political wars over the slavery debate. When it was officially opened to settlement by the U.S. government in 1854 with the Kansas–Nebraska Act, conflict between abolitionist Free-Staters from New England and pro-slavery settlers from neighboring Missouri broke out over the question of whether Kansas would become a free state or a slave state, in a period known as Bleeding Kansas. On January 29, 1861, Kansas entered the Union as a free state, hence the unofficial nickname "The Free State". Passage of the Homestead Acts in 1862 brought a further influx of settlers, and the booming cattle trade of the 1870s attracted some of the Wild West's most iconic figures to western Kansas.