From The Writer's Almanac:
It's the second Sunday in May, which is Mother's Day here in the United States. It's Mother's Day in other countries, too, including Denmark, Italy, Venezuela, Turkey, Australia, and Japan. It's the biggest day of the year for long-distance telephone calls.
A woman named Anna Jarvis was the person behind the official establishment of Mother's Day. Her mother, Anna Reeves Jarvis, had a similar idea, and in 1905 the daughter swore at her mother's grave to dedicate her life to the project. She campaigned tirelessly for the holiday. In 1907, she passed out 500 white carnations at her mother's church, St. Andrew's Methodist Episcopal Church in Grafton, West Virginia — one for each mother in the congregation. In 1912, West Virginia became the first state to adopt an official Mother's Day, and in 1914 President Woodrow Wilson made it a national holiday.
Anna Jarvis became increasingly concerned over the commercialization of Mother's Day. She said, "I wanted it to be a day of sentiment, not profit." She was against the selling of flowers, and she called greeting cards "a poor excuse for the letter you are too lazy to write." Nevertheless, Mother's Day has become one of the best days of the year for florists. When Anna Jarvis lived the last years of her life in nursing home without a penny to her name, her bills were paid, unbeknownst to her, by the Florist's Exchange.