Mulligan (September 28, 1866–March 25, 1916) was an American sculptor born in Riverdale, County Tyrone, Ireland.
He immigrated to America at the age of 17 and found work as a stone cutter in Pullman, Illinois, near Chicago.
He studied at the School of the Art Institute of Chicago with Lorado Taft, who was also working as an assistant at the time.
During the Columbian Exposition in 1893 Taft made Mulligan the foreman of the workshop producing a large amount of sculpture for the exhibition.
Luke's Hospital accompanied by his wife and three children.
At the time of his death, he had just been awarded a commission to build his design of a statue of Mad Anthony Wayne in Fort Wayne, Indiana.He was buried at Mount Greenwood Cemetery.