The holiday was celebrated on different dates, depending on the state. In the early 19th century, the last Thursday in November became the customary date for most states, coinciding with the Evacuation Day holiday, commemorating the day the British left the US after the War of Independence. Eventually, Thanksgiving Day replaced Evacuation Day.
In the end, President Abraham Lincoln established a national Thanksgiving Day for all states for the last Thursday in November. The president’s decision was influenced by New England resident Sarah Josepha Hale, who wrote letters to politicians for nearly 40 years advocating an official holiday.
