The 1891 U.S. National Championships (now known as the US Open) was a tennis tournament that took place in June and August of 1891. The women's tournament was held from June 23 to June 27 on the outdoor grass courts at the Philadelphia Cricket Club in Philadelphia, Pennsylvania. The men's tournament was held from August 22 to August 31 on the outdoor grass courts at the Newport Casino in Newport, Rhode Island. It was the 11th U.S. National Championships and the second Grand Slam tournament of the year.:
Oliver Campbell defeated Clarence Hobart 2âÂÂ6, 7âÂÂ5, 7âÂÂ9, 6âÂÂ1, 6âÂÂ2
Mabel Cahill defeated Ellen Roosevelt 6âÂÂ4, 6âÂÂ1, 4âÂÂ6, 6âÂÂ3
Oliver Campbell / Bob Huntington defeated Valentine Hall / Clarence Hobart 6âÂÂ3, 6âÂÂ4, 8âÂÂ6
Mabel Cahill / Emma Leavitt Morgan defeated Grace Roosevelt / Ellen Roosevelt 2âÂÂ6, 8âÂÂ6, 6âÂÂ4
Mabel Cahill / Wright defeated Grace Roosevelt / Lee 6âÂÂ4, 6âÂÂ0, 7âÂÂ5 âÂÂ
â - <small>The Mixed Doubles event was not an official event in 1891</small>