The United States celebrates Mother's Day on the second Sunday in May. In the United States, Mother's Day was loosely inspired by the British day and was imported by social activist Julia Ward Howe after the American Civil War. However, it was intended as a call to unite women against war. In 1870, she wrote the Mother's Day Proclamation as a call for peace and disarmament. Howe failed in her attempt to get formal recognition of a Mother's Day for Peace. Her idea was influenced by Ann Jarvis, a young Appalachian homemaker who, starting in 1858, had attempted to improve sanitation through what she called Mothers' Work Days. She organized women throughout the Civil War to work for better sanitary conditions for both sides, and in 1868 she began work to reconcile Union and Confederate neighbors. In parts of the United States it is customary to plant tomatoes outdoors after Mother's Day (and not before).

When Jarvis died in 1907, her daughter, named Anna Jarvis, started the crusade to found a memorial day for women. The first such Mother's Day was celebrated in Grafton, West Virginia, on 10 May, 1908, in the church where the elder Ann Jarvis had taught Sunday School. Grafton is the home to the International Mother's Day Shrine. From there, the custom caught on — spreading eventually to 45 states. The holiday was declared officially by some states beginning in 1912. In 1914 President Woodrow Wilson declared the first national Mother's Day, as a day for American citizens to show the flag in honor of those mothers whose sons had died in war. Nine years after the first official Mother's Day, commercialization of the U.S. holiday became so rampant that Anna Jarvis herself became a major opponent of what the holiday had become. Mother's Day continues to this day to be one of the most commercially successful U.S. occasions. According to the National Restaurant Association, Mother's Day is now the most popular day of the year to dine out at a restaurant in the United States.