William Leidesdorff, who the San Francisco Museum provides great information about, and whose 200th year birthday celebration is this year, was the owner of the 35,000 acre Mexican land grant described by Wikipedia, that inspired the naming of the American River and encompassed much of the Parkway on the south shore of the American, as this article from Human Events notes.
“…. William Alexander Leidesdorff, arguably one of the best kept secrets in the history of the West and the creation of the state of California.
“Mr. Leidesdorff was born in St. Croix in 1810 to a Jewish sugar planter and a black plantation worker. Next year is his 200th birthday, a time to reflect on his role in history and the unique dimensions of American life.
“After working for his father’s cotton business in New Orleans, he moved to Yerba Buena, the Mexican town that would later become San Francisco where the efflorescence of his career emerged.
“In 1844 he became a Mexican citizen and was granted 35,000 acres on the American River. It was on this property that gold was discovered shortly before he died in 1848. That discovery made him the first black millionaire in the United States.
“After becoming a successful merchant, he was appointed Vice Consul of the United States to Mexico, albeit this position was not formally recognized by Washington, D.C. until after his death. Similarly, he did not receive formal acceptance as the first black American diplomat even though he was integrally involved in the establishment of the republic of California.
“As a member of the San Francisco City Council, he donated land and authorized the building of the first public school in San Francisco with an expenditure of $1000. He launched the first steam powered schooner in the bay and held the first horse race in the state.”