He was a backer of the Life Saving Service, later merged into the United States Coast Guard. He was also known as the "letter carriers' friend" because of his support for paid benefits and a 40-hour work week for U.S. Post Office employees. In 1891, grateful postal workers raised $10,000 to erect a statue of Cox by sculptor Louise Lawson in New York City. It was originally placed near his home on East 12th Street but was later moved to its present location in Tompkins Square Park. It depicts Cox orating and has been criticized as a poor likeness. The statue became controversial in 2020.