The history of the modern U.S. Capitol, the iconic seat of American government, is also the history of America's most tumultuous years. As the majestic new building rose above Washington's skyline, battles over slavery and secession ripped the country apart. Ground was broken just months after Congress adopted the Compromise of 1850. Workers began to bolt the Capitol's nine-million-pound cast-iron dome into place in 1856. The Statue of Freedom was placed atop it in 1863, five months after the Battle of Gettysburg. Little known is the greater irony: America owes the building's scale and magnificence to Jefferson Davis, who remained the Capitol's staunchest advocate up until the week he left Washington to become president of the Confederacy. Davis' protege and the engineer in charge was army captain Montgomery Meigs, who as Lincoln's quartermaster general of the Union Army would never forgive Davis' betrayal of the nation. The Capitol's brilliant architect, and Meigs' longtime rival, was Thomas U. Walter, a Southern sympathizer who would turn fiercely against the South and all who had betrayed the Union.