Before the American colonies switched to the Gregorian calendar in 1752, on what date did their new year start?

The story behind the answer

March 25th is correct because, under the Julian “Old Style” calendar used by Britain and its American colonies, the legal new year began on Lady Day—the Feast of the Annunciation. When Britain adopted the Gregorian calendar in 1752, it moved New Year’s Day to January 1 and also dropped 11 days to realign with the sun (September 2 was followed by September 14).

Context: Dates between January 1 and March 24 before 1752 are often “dual-dated” (e.g., George Washington’s birthday: Feb 11, 1731 O.S. = Feb 22, 1732 N.S.). A memory aid: “Lady Day launches the year.” The legacy lingers in Britain’s tax year, which starts on April 6—roughly March 25 plus the 11 days lost in 1752.