Holidays September 17, 2024 4:23 pm What is Constitution Day? Constitution day is a federal holiday that commemorates the signing of the U.S. Constitution in 1787. US & World Videos 0:42 Bakery in Carson vandalized, burglarized by homeless woman 7:07 Mariska Hargitay wasn't allowed to touch her Olivia Benson costume in the Smithsonian 6:09 Nate Bargatze read Heidi Gardner's lines on ‘SNL' because he's colorblind 1:56 Halle Bailey and DDG split less than one year after son's birth 3:02 Kim Kardashian demands Menendez brothers release as prosecutors review new evidence