Wikipedia adds some further, posthumous details:
R. Wilson McCoy (1902-1961) was the second artist on the (still running) The Phantom comic strip. He started out as Ray Moore's assistant, but when Moore retired from the strip after a war-injury, McCoy took over the entire strip (1949).
McCoy is well known for his unique, naive style of drawing. Unlike Ray Moore, he always drew with tremendous attention to details, and used photographic references for every drawing, having his family and friends pose for him and act out the different situations happening in the stories he worked on.
Like Phantom-creator Lee Falk, Wilson McCoy was a world traveler with an adventurous spirit. He frequently visited far off jungles, and visited several native tribes, among them the Ituri tribe, consisting of pygmies, much like the Bandar tribe in the Phantom strip.
Wilson McCoy studied at the School of the Art Institute of Chicago, The American Academy, and Washington University's School of Fine Arts, where he later served on the faculty. Working as a commercial artist, he made paintings for Liberty Magazine covers, calendars, prints, pin-ups and advertisements for major companies. When his friend Ray Moore served in the military during WWII, McCoy took over the responsibilities of illustrating the syndicated newspaper strip, 'The Phantom'. His wife, Dorothy, did the lettering. McCoy continued drawing the strip until his death in 1961, after which it was continued by Bill Lignante for a short while, and then Sy Barry.
Robert Wilson McCoy was born in Troy, Missouri on April 6, 1902. McCoy died on July 20, 1961 after a heart attack, with Sy Barry succeeding him on the Phantom. He was survived by his wife Dorothy and two children, Robert and Carol.