Yesterday was a historic day. On January 20th, 2009, Barack H. Obama was sworn in as the 44th President of the United States of America - the first African-American ever to hold the office of U.S. Commander-in-Chief. The event was witnessed by well over one million attendees in chilly Washington D.C., and by many millions more through coverage on television and the Internet. Collected here are photographs of the event, the participants, and some of the witnesses around the world. ( 48 photos total