The dome was completed in 1863, and Brumidi painted it over the course of eleven months at the end of the American Civil War.
Brumidi had worked for three years in the Vatican under Pope Gregory XVI, and served several aristocrats as an artist for palaces and villas, including the prince Torlonia.
Washington, the first U.S. president and commander-in-chief of the Continental Army during the American Revolutionary War, is allegorically represented, surrounded by figures from classical mythology.
Forming a circle between Liberty and Victory are 13 maidens, each with a star above her head representing the original Thirteen Colonies.
Several of the maidens have their backs turned to George Washington, said to represent the colonies that had seceded from the Union at the time of painting.