Ward was noted for his specialized collection of United States revenue stamps which contained the only complete set of inverted centers, and which was retained by Hiram Edmund Deats in the 1950s.

Philip Ward created and sold important collections of philatelic material, such as large blocks of classic United States postage stamps, postage stamps of Japan, and worldwide postage stamps whose centers had been inverted, causing them to be expensive rarities.

He also assembled and sold unusual and rare collections, such as Match and Medicine stamps and presidential letters and autographs.

Ward was one of the first philatelists to recognize the importance of the issuance and collection of first day covers of United States stamps.

Ward was recognized for his achievements by being named to the American Philatelic Society Hall of Fame in 1966.