The Chinese Merchant's Associaton was built in 1950 by Poy Gum Lee. The Museum of Chinese America describes the building as, "a boxy modernist block with modest Chinese decorative motifs...the most iconic building in Chinatown, the pagoda-topped On Leong Tong building typified Lee’s Chinese modern style." Poy Gum Lee, born and educated in New York, was the architectural consultant for the Chinese Consolidated Benevolent Association. This was the first building to be constructed in a style reflective of Chinese-American culture. Additionally, Poy Gum Lee was the first well-known architect of Chinese-American descent to build in Chinatown.

The building houses the On Leong Tong, or the Chinese Merchants Association, a tong society established in 1893. This building was part of the tong's territory. Upon its formation, the On Leong Tong feuded with the Hip Sing Tong over control of the area. Tongs were mutual aid societies established to protect Chinese families and businesses against racism and prejudice in the United States. Many tongs were quickly associated with street gangs as violence between tongs was not uncommon. In extension, tongs found profit in appealing to vices, and many tongs were sustained by running brothels, opium dens, and gambling houses. However, tongs acted as the court and police force for Chinese-American communities, providing a semi-legitimate structure for communities otherwise unprotected by the government.

The On Leong Tong is still operational and maintains over 3,000 members.