The 1891 U.S. National Championships 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.: US Open 1891: August 22–22, 1891. Men's singles: Oliver Campbell — 2nd major title. Women's singles: Mabel Cahill. Wiki link