Mary Ludwig Hays, often referred to as "Molly Pitcher," is best known for her role as a combat supporter during the American Revolution. She is celebrated for taking over her husband's cannon duties at the Battle of Monmouth when he was incapacitated, thus directly contributing to the war effort on the battlefield.
In contrast, Betsy Ross is recognized for her contributions to the symbolism of the Revolution, particularly for allegedly sewing the first American flag. While her work with textiles symbolized national identity and Unity, it was more a matter of craftsmanship and patriotism than direct involvement in combat.
In summary, while Mary Ludwig Hays contributed actively as a combat supporter on the battlefield, Betsy Ross contributed symbolically through her creation of the flag, highlighting different types of involvement in the Revolutionary War.