This dataset was compiled for an article published on the Guardian 11 September 2015: 'Battle of the sexes: charting how women in tennis achieved equal pay'. I found it (surprisingly) difficult to find prize money data for three of the four Grand Slams, so I'm sharing the records here for others who might be interested.
This dataset consists of men's and women's singles winners' prize money for each Grand Slam from 1968 to 2015. For the Australian Open, data is provided since 1971; two tournaments were held in 1977, but no women's prize money data is available for that year; and no tournament was held in 1986.
Prize money is noted in local denominations: US Open (USD), Australian Open (AUD), Roland Garros (FRF through 2001, EUR since 2002), Wimbeldon (GBP).
SOURCES: United States Tennis Association, Fédération Française de Tennis, Wimbledon.com, Tennis Australia (via The Guardian)