Mary Greenleaf Leavitt was an educator and successful orator who became the first round-the-world missionary for the Woman's Christian Temperance Union (WCTU). Setting out on virtually non-stop worldwide tours over a decade, she "went to all continents save Antarctica," where she crusaded against alcohol and its evils including domestic violence; and advocated for women's suffrage and other equal rights such as higher education for women. In 1891 she became the honorary life president of the World's WCTU.

The Woman's Christian Temperance Union (WCTU) is an international temperance organization. It was among the first organizations of women devoted to social reform with a program that "linked the religious and the secular through concerted and far-reaching reform strategies based on applied Christianity." It plays an influential role in the temperance movement. Originating among women in the United States Prohibition movement, the organization supported the 18th Amendment and was also influential in social reform issues that came to prominence in the progressive era.