At the time, the company was one of the four largest leather-tanning operations in the United States.
He and his brother, Arthur, studied modern methods of tanning leather practiced throughout the world[3] and were recognized as authorities on the industry and the scientific principles involved.
[4] A short time before World War I,[4] they established a research department at Columbia University for the tanning industry which was paid for by A. F. Gallun & Sons and the university.
Gallun was married to Hedwig Mann, of Two Rivers, Wisconsin, who died in 1932.
[9] Gallun's mansion, built in 1914,[10] is part of the NRHP Kenwood Park-Prospect Hill Historic District.