These papers, dating from 1888 to 1994, provide vivid accounts of the missionary experiences of Paul and Helen Hayes (1921-1935), details of Paul's ministry after returning to the United States, and their family and social lives. Paul and Helen met, as they often quipped, "on a slow boat to China." Although sent under the auspices of different boards, their mutual devotion to mission work, shared theological ideals, and sheer enjoyment of each other's company cemented their relationship. They studied together at the University of Nanking Department of Missionary Training, dated frequently, and corresponded much while apart. After deciding to unite in marriage, Helen realized that she must transfer her affiliation from the Reformed Church Foreign Mission Board to the Methodist Episcopal Church Foreign Mission Board so that she could serve with her husband. Since the Methodist Board was obligated to pay the costs incurred by the Reformed Board for her service, Helen often teased Paul that she had been "bought and paid for like a Chinese bride." Due to the Depression in the United States, the Methodist Board could no longer support the Hayes' missionary work in China. They were asked to return to the States in 1935 and serve in the Methodist Church, first in Minneapolis, followed by an appointment in North Dakota, and back to Minnesota where they remained for the rest of their lives. Paul "retired" three times, but essentially continued to minister in various capacities until the disabilities associated with advancing age made it impossible.