The Denver Women's Social Union Club, a club for poor and working-class women, was founded as a mutual-aid society in November 1898 by members of the social science department of the Women's Club of Denver. The club was started to benefit women and their families living in the Delgany neighborhood. The social science department of the Women's Club of Denver ran a variety of social programs in the Delgany neighborhood ranging from a night school and Travelling Art Gallery to free baths. The Delgany Library was housed in the Railroad Mission at 19th and Wewatta Streets and it was here that the initial meeting of the Social Union was held during which women resolved to form an organization to meet the needs of the people in the area. Mary C.C. Bradford, a member of the Women's Club of Denver, was later considered the mother of the Social Union because of her help in its early years. She christened the mutual-aid organization "The Social Union," a name that was retained until 1921 when it was reorganized as a philanthropic and social organization and renamed "The Denver Women's Social Union Club." The Penny Provident Fund, established for members of the Social Union, became the Social Union Savings Bank in 1903 in which club members deposited what savings they could. This money was used as an emergency fund to aid needy members in hard times. Mary C.C. Bradford described the benefits of the Social Union to its members: "The uplift that the meetings have given to these toil-worn, shut-in lives is incalculable. Vistas of beauty have been opened, stronger thinking stimulated, home problems solved, and best of all, the sense of loving unity established between themselves and their more fortunate sisters." (from Some Work of the WCD in A History of the Women's Club of Denver by Mary Sinton)

Meetings generally consisted of business followed by refreshments and a program. During the meeting, women would suggest those in need whom the organization might assist in one way or another and plan benefits such as cake baking contests or raffles. The money thus earned would go to fund the Union's Activities. For example, during 1908-1909, the women of the Social Union made visits to homes and hospitals and delivered bouquets, jellies, fruits, bundles of clothing, a total of eight tons of coal, and 14 dollars to the sick and needy. "We also have endeavored to answer every call of sickness and distress that has come to us, as well as to visit every member of the S.U. who has been ill." (from Minutes 1908-1916) The programs were organized by individual members and included a variety of presentations. For example, one meeting on March 29, 1923 included a talk by Mary C.C. Bradford, who gave an "account of [the] compulsory educational bill and urged women to sign it," followed by a program of "fancy dancing" presented by Virginia Jardt and Janice Goalstone. (from Minutes 1923-1924)

The last meeting of the Denver Women's Social Union Club was held in 1973 and the remaining 25 members decided to close the books on November 4, 1977 "due to [the fact that] many of our faithful members passed on." (from Minutes 1957-1973)