This beautiful painting in the rotunda is huge, the painted figures are 15' tall, however from the floor it is somewhat difficult to make out who is up there. Following is information about the painting from Wikipedia's article on "The Apothesis of Washington":
The Apotheosis of Washington is the very large fresco painted by Italian artist Constantino Brumidi in 1865 and visible through the oculus of the dome in the rotunda of the United States Capitol Building. The fresco is suspended 180 feet above the rotunda floor and covers an area of 4664 square feet. The figures painted are up to 15 feet tall and are visible from the floor below. The dome was completed in 1863, and Brumidi painted it over the course of 11 months at the end of the Civil War. He was paid $40,000 for the fresco.
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. He immigrated to the United States in 1852, and spent much of the last 25 years of his life working in the Capitol. In addition to The Apotheosis of Washington he designed the Brumidi Corridors.
The Apotheosis of Washington depicts George Washington ascending to the heavens and becoming a god (apotheosis). 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. Washington is draped in purple, a royal color, with a rainbow arch at his feet, flanked by the goddess Victory (draped in green, using a horn) to his left and the goddess Liberty to his right. Liberty wears a red cap, symbolizing emancipation, from a Roman tradition where sons leaving the home would be given a red cap. She holds a fasces in her right hand and an open book in the other.
Forming a circle between Liberty and Victory are 13 maidens, each with a star above their heads, representing the original 13 colonies.
Surrounding Washington, the two goddesses, and the 13 maidens are six scenes lining the perimeter, each representing a national concept allegorically: from directly below Washington in the center and moving clockwise, "War," "Science," "Marine," "Commerce," "Mechanics," and "Agriculture".
Use the link below to read more about the interpretations of the 6 allegorical scenes.