An excerpt from an OUPblog article published on 13th January 2017, written by Donald A. Ritchie, author of The U.S. Congress: A Very Short Introduction.
"Given our constitutional separation of powers, it seems odd that a presidential inauguration takes place on the Capitol steps. Like so much else in American history, the story begins with George Washington. In 1789, the First Congress met in New York City, where it proceeded to count the electoral ballots, an easy task since the vote had been unanimous. Congress sent notification to the president-elect in Virginia, and then swore in Vice President John Adams, who presided over the Senate before Washington ever arrived in New York.
As the only functioning branch of the new federal government at the time, Congress appointed a joint committee to conduct the presidential inauguration. Although the House of Representatives occupied the largest chamber in New York’s Federal Hall, the Senate had a balcony that would enable large crowds outside to witness the ceremony..."
Discover more: Read the rest of the article on the OUPblog.