Joseph A. [Argyle] Leonard [b. Jan. 1, 1850] - businessman, architect, contractor, designer, builder, property owner. Leonard designed and built several Queen Anne style houses throughout the island city in 1890s.  He moved to Alameda with his family in 1887.

"The biggest concentration of Leonard-built houses in Alameda was an extended district of nearly 70 houses in the vicinity of Chestnut Station, developed between 1889 and 1896, and popularly known as 'Leonardville.'"¹

Sources:

1. Minor, Woody. "Happy birthday, Mr. Leonard!" Alameda Journal. 1-4 Jan. 1993.