Robert Goodloe Harper was an American soldier and politician. He was a member of the United States Senate from Maryland, serving from January 1816 until his resignation in December of the same year. He also served in the South Carolina House of Representatives (1790–1795), the U.S. House of Representatives from South Carolina (1795–1801), and in the Maryland State Senate. He is best remembered for the phrase, "Millions for defense, but not one cent for tribute" in connection with the XYZ Affair. The town of Harper, Liberia, is named after him.

The 3rd United States Congress was a meeting of the legislative branch of the United States federal government, consisting of the United States Senate and the United States House of Representatives. It met at Congress Hall in Philadelphia, Pennsylvania from March 4, 1793, to March 4, 1795, during the fifth and sixth years of George Washington's presidency.