Harry Wesslund was born on July 22, 1912 in Stockett, Montana. His family (including parents John and Hulda and siblings Victor and Pearl) moved to Grand Rapids sometime between 1915 and 1918. Harry attended Union High School, graduating in 1929. According to his senior yearbook, he was the Art Editor of “Unionite,” the Chairman of the Decoration Committee; President of the Science Club; Art Staff for Aurora (the yearbook) and belonged to Hi-Y and the Boy's Glee Club. The yearbook also noted that he attended Sibley School. The May 1928 Unionite lists results of the Junior class elections, with Harry Wesslund voted the “best all around boy.”

Harry attended Grand Rapids Junior College after high school, where he reportedly studied art. According to the city directories, Harry worked as a sign writer for Wurzburg Dry Goods (1930 and 1935) and as a card writer for Sears Roebuck (1934). He also worked for Herpolsheimers, identified as an “artist and designer extraordinaire” in a newsletter. Harry's older brother, Victor, also worked as a sign writer for Wurzburg's (1929, 1932).

On April 3, 1943 Wesslund enlisted in the United States Army and served as a private in World War II. A May 1954 Peninsular Club Magazine article states that Wesslund served in the photographic intelligence service in Germany and France, specializing in analyzing aerial photographs. The article also indicates that upon returning from the war in 1946, Wesslund started his own design company, Custom Displays, Inc. However, the first directory listings for the company (1946 through 1955) identify the officers as Cornelius VanWesten, Jr. (Harry's brother-in-law) and Victor Wesslund. During this time, Harry Wesslund is listed as an artist.

From 1960 to 1970, Harry and his wife Wanda are listed as the officers of the company, with Harry generally identified as the President and Treasurer and Wanda as the Vice President and Secretary. Wanda's obituary indicates that she and Harry co-owned and operated the business. By 1975, their son John is listed as the Vice President and by 1980 as the President. After Harry's death in 1985, the company is listed with John and Wanda as President and Vice President for a few years, and then is no longer found in the directories.