Mary McHenry was born in 1855. Her father was Judge John McHenry, a former Louisiana Supreme Court Justice, who had moved to California just a few years before her birth.

In 1879, Mary McHenry graduated from UC Berkeley; then, in 1882, she became the first woman to graduate from Hastings School of Law in San Francisco. She was the valedictorian.

Mary McHenry was standing on the shoulders of giants. Just a few years earlier, the law school only admitted white men, but that changed when suffragists Clara Foltz and Laura Gordon organized and fought their way through the courts, determined to make the school let women in.

Their case received national publicity. The fact that the first graduate of Berkeley's law school was valedictorian made the victory all the sweeter.

Clara Foltz wrote to Mary McHenry, “[Y]ou scored one for your sex in carrying off the honor of an institution that but recently scanted the idea of a woman aspiring to be a lawyer. [...] I rejoice in your success . . . that at the first public graduating exercises of Hastings College of Law, a bright and beautiful young girl comes off with the honors of the class.”

The year following her graduation, Mary McHenry married William Keith, a Scottish-American painter famous for his California landscapes. She practiced law for a short time, but after marrying she shifted her focus to women's suffrage organizing.

McHenry Keith was a leader of the Berkeley Political Equality Club, one of the largest suffrage organizations on the West Coast, where she helped organize the Women's Congress held in Berkeley to drive the suffrage referendum in 1895 and 1896.

Despite the energetic campaign that mobilized thousands of women across California, the amendment failed to pass with 45% voting yes and 55% voting no. Urban areas in particular were resistant to the amendment; though the reasons are complex, suffragists attributed its failure to the liquor lobby and the belief that women would vote to ban alcohol.

In 1908, a few years before women's suffrage would be put to a vote again in California, Mary McHenry Keith was still working tirelessly for equality. American women were outraged at the treatment of suffragists in England, who were being jailed.

Mary's husband William, also an ardent suffragist, worried for his wife's safety. In a newspaper interview, Mary remarked, “My husband has warned me to go slowly, because he is afraid I may be put in prison, too [...]. I think equal suffrage will be realized by us within a very few years.”

Leading up to the 1911 vote for suffrage, Mary McHenry Keith wrote a weekly column for the Oakland Inquirer, spoke and financially supported the cause, and exchanged letters with other prominent activists like Susan B. Anthony. Mary's husband William painted a portrait of Anthony.

By 1911, five other states had won women's right to vote, and none of these states had suffered any negative consequences like was feared. California suffragists gained more allies as progressives broke though the conservative dominance of the California legislature, and reformist movements were changing the landscape.

This time around, suffragists altered their messaging, “downplay[ing] divisive issues like prohibition," instead presenting enfranchising women as "one among many other reforms that would clean up local governments by reducing the power of political machines and monopolistic corporations.”

Further, the 1911 movement was bolstered by women from many different intersections, like working women, labor activists, women of color, church groups, and women's clubs.

According to the California Courts Newsroom, Mary McHenry Keith's leadership was key to the campaign's success. Her messaging emphasized the need for co-education and utilized modern technology like automobiles and telephones to reach rural voters. Keith also rented the house that served as headquarters for the Equal Suffrage League.

The measurement passed, making California the sixth state to grant women the right to vote. The Nineteenth Amendment, which granted women the right to vote, would not be passed until nine years later.

Though women's right to vote was a tremendous victory in California, Mary McHenry Keith unfortunately could not celebrate with her partner and ally, William Keith, as he passed only a few months earlier.

After William's death, Mary catalogued more than 100 pieces of his work and often loaned out his paintings for public display.

McHenry Keith continued the fight for women's suffrage in other states and nationally. She also worked for animal rights, supporting the Humane Society, Humane Society, the California Audubon Society, and the Society for the Prevention of Cruelty to Animals (SPCA).

Mary McHenry Keith died in Berkeley on October 13, 1947, at the age of 91.