The creation of Dan Flagg launched Sherwood forward in his profession. He was invited to lunch with President Lyndon B. Johnson at the White House, joining four other famed military cartoonists (Milton Caniff, Mort Walker, Bill Mauldin and Wunder). He was a presenter at the 1964 World's Fair in New York, and "Dan Flagg Day" ceremonies were held in New York City and Philadelphia. Sherwood researched his strip exhaustively, visiting Marine installations, talking to recruits and generals, and studying the Corps and the subjects of planned storylines. As a result, Sherwood was commended for the authenticity of his artwork (after one strip contained a drawing of the U.S. Embassy in New Delhi, India, Sherwood received a letter from the architect of the building, Edward Durell Stone, praising its accuracy) and for the timeliness of his storylines (after one adventure involving Cuban relations, a group seeking to oust Fidel Castro wrote to Sherwood to ask for Dan Flagg's cooperation). Sherwood consistently appeared on behalf of the Marine Corps, with whom he shared a mutual respect; the Marine Corps Commandant, David Shoup, met with Sherwood and called him "a master of his art." Among his commendations, Sherwood received a plaque from the U.S. Marine Corps Combat Correspondents Association and a citation from the National Press Club.
