On March 4, 1861, Abraham Lincoln was sworn in on the steps of an unfinished U.S. Capitol building, making him the 16th president of the United States.

Photos from that day show around 25,000 people crowding the Capitol steps -- a far cry from the first inauguration of President Barack Obama in 2009, where crowds were estimated at upwards of 1.8 million people.

Below is a photo from the March 4, 1861, inauguration of Abraham Lincoln: