He was a distant relation of Thomas Corwin Mendenhall, superintendent of the United States Coast and Geodetic Survey.

Mendenhall had joined the Survey in 1894, fresh from Ohio Normal University, and had mapped in the Appalachian coal fields.

The appropriations were not restored to earlier levels until the late 1930s, shortly before the outbreak of World War II, but the Survey subsisted, even grew, on funds transferred from agencies the Franklin D. Roosevelt administration formed to combat the Great Depression.

[citation needed] In 1943, as the U.S. Government began planning for the post-World War II era, Director Mendenhall, who had served two years beyond the mandatory retirement age by presidential exemption, was succeeded by William Embry Wrather.

In spite of the difficult times — the Great Depression years and the beginning of World War II — in which he held the position, he encouraged the Survey, as he had the Geologic Branch, to emphasize the necessity of basic research and created an environment in which, in the words of the Engineering and Mining Journal, "scientific research, technical integrity, and practical skill could flourish."