House Speaker John Boehner says the 10,000 lights on the U.S. Capitol Christmas Tree represent the "everlasting light" that entered the world with the birth of Jesus Christ.
Boehner hosted Tuesday evening's lighting of the 65-foot spruce from Colorado.
Hundreds of people gathered outside the Capitol with cameras in tow to catch the lighting ceremony.
Angelique Earley of Alexandria said, "It's the biggest Christmas tree we've ever seen. I think the biggest we'll ever see!"
Earley is sharing the holiday spirit with her 3-month-old son. She joined many other parents making the tree lighting a tradition.
"We are super big Christmas nuts," added Misty Sabol, also of Alexandria. "It's particularly exciting, because I think that Canon is getting old enough now where he'll be able to remember things."
Eagle Scout Ryan Shuster of Colorado Springs flipped the switch as the crowd cheered, and the U.S. Air Force Band played "O Christmas Tree" and other holiday classics.
Boehner said the Christmas story should inspire the kind of joy felt by the shepherds of Bethlehem as the angels heralded Christ's birth.
The tree will be lit each night until the day after Christmas.
There's still plenty of time left to check out the tree for yourself. It will be lit from dusk until 11 p.m. every night until Dec. 26.
The Associated Press contributed to this report.