Abstract M. Clay Church (1877-1966) was a businessman from Grand Rapids, Michigan. He worked for his father's company, the Couple Gear Co., which produced the worlds first truck trailers and designed a truck with a motor for each wheel. Church lived in Massachusetts from the late 1920s through the early 1960s, operating the Church Motor Company. Later, he worked as an insurance executive. A majority of his diary entries relate to his business dealings: what happened at the factory, who he...