Three-Fifths Compromise: The first instance of black slaves in the United States of America being counted as three-fifths of persons (for the purpose of taxation), in a resolution of the Congress of the Confederation. This was later adopted in the 1787 Constitution.

The Three-fifths Compromise, also known as the Constitutional Compromise of 1787, was an agreement reached during the 1787 United States Constitutional Convention over the inclusion of slaves in counting a state's total population. This count would determine the number of seats in the House of Representatives, the number of electoral votes each state would be allocated, and how much money the states would pay in taxes. Slaveholding states wanted their entire population to be counted to determine the number of Representatives those states could elect and send to Congress. Free states wanted to exclude the counting of slave populations in slave states, since those slaves had no voting rights. A compromise was struck to resolve this impasse. The compromise counted three-fifths of each state's slave population toward that state's total population for the purpose of apportioning the House of Representatives, effectively giving the Southern states more power in the House relative to the Northern states. It also gave slaveholders similarly enlarged powers in Southern legislatures; this was an issue in the secession of West Virginia from Virginia in 1863. Free black people and indentured servants were not subject to the compromise, and each was counted as one full person for representation.

The Congress of the Confederation, or the Confederation Congress, formally referred to as the United States in Congress Assembled, was the governing body of the United States from March 1, 1781, until March 3, 1789, during the Confederation period. A unicameral body with legislative and executive function, it was composed of delegates appointed by the legislatures of the thirteen states. Each state delegation had one vote. The Congress was created by the Articles of Confederation and Perpetual Union upon its ratification in 1781, formally replacing the Second Continental Congress.

April 18 is the 108th day of the year in the Gregorian calendar; 257 days remain until the end of the year.