William Sanger was born in 1873 and he began his career outlooks as an architect with interest in radical politics. He and his family moved to New York City, and in that city he met Margaret. Together they joined the Socialist Party and participated in radical events such as the 1913 Peterson Strike Pageant.

As draftsman for a quite fashionable firm of McKim, Mead and White, Sanger became increasingly bored with architecture and he became more aware of his desire for painting when he saw the 1913 Armory Show. Impressed by European art, Sanger and his family moved to Paris to study art in October 1913. His wife engaged in the research of contraceptive techniques. Sanger's family returned to New York while William stayed and continued his work in painting. The physical distance along with Margaret's increasingly frustration with William, and William's traditional beliefs on marriage and domestic demands created a strain in their marriage.

In 1914, William Sanger was forced to return home where he was also pushed to deal with his wife's request for separation. While his wife continued her research and literature work in contraceptives, William contributed drawings to her journal, "The Birth Control Review". After returning to New York, William faced divorce in 1921 and his career as a painter was not successful. He had to take a position as an architect with the New York City Department of Water Supply, Gas, and Electricity.

Reference: The Margaret Sanger Papers Electronic Edition: Maragert Sanger and the Woman Rebel, 191401916, eds. Esther Katz, Cathy Moran Hajo and Peter Engelman.