margaret osborne dupont (born margaret evelyn osborne; march 4, 1918 – october 24, 2012) was a world no. 1 american female tennis player. dupont won a total of 37 singles, women's doubles, and mixed doubles grand slam titles. she won 25 of her grand slam titles at the u.s. championships, which is an all-time record. he was born in joseph, oregon.