2024 Leidesdorff Birthday Tour and Dinner Celebration

On this day, October 23, 1810, William Alexander Leidesdorff Jr. was born in St. Croix, then Danish Virgin Islands. He was the oldest son of Wilhelm Leidesdorff, a Danish sailor of Jewish descent, and Anna Marie Sparks, a woman African Cuban descent who lived a full life together as husband and wife.

By the age of 24, the William Alexander Leidesdorff Jr. had migrated to New Orleans to become an American citizen, obtained Master’s license as a ship captain and spent several years operating from the Port of New Orleans to destinations throughout the Caribbean, Gulf of Mexico and Eastern US Seaboard.

Port of New Orleans Negro Seamen Acts, proved the final call to leave New Orleans and relocate his lucrative Maritime career. He secured the ship Julia Ann from New York, visited his mother in St. Croix and sailed around the Horn, to Mexican Capital of Monterey, Alta California, in 1841.

William settled in Yerba Buena (today's San Francisco) and established commercial relations throughout the vast Pacific Rim, trading with other international merchants.


Leidesdorff became the representative of the Russian American Fur Company and handled John Sutter’s payments to the Russian Government after Johan Sutter purchased Fort Ross.

William became a Mexican citizen and took judicial possession of his 35,521 acre land grant he named Rancho Rio de Los Americanos along the south of the American River from what is today Bradshaw Road in Rancho Cordova, CA to the El Dorado County line, in Folsom, CA enrolled in 2024 as the William Alexander Leidesdroff Jr., Memorial Highway. (ACR 131 Cox)

Honorable William Alexander Leidesdorff, Jr. was appointed by Thomas Larkin as the U.S. Vice Consul to Mexico, Alta California and his documented report of the Bear Flag Revolt, is the official beginning of the acquisition of California during the US/Mexican War.

In November 1847, he captained his steam vessel purchased from his Russian clients in Sitka, Alaska. The 37 foot, side wheel steam ship named the Sitka, famous voyage upstream through the winding California Delta, up the Sacramento River is immortalized on the California State Seal helping to facilitate modern agriculture and passenger transportation.

Leidesdorff passed away on May 18, 1848 from what was called "brain fever" at the age of 36 in San Francisco just days after he received official reports of vast sums of gold on Leidesdorff Ranch along the American River.

Leidesdorff was one of the major founders of the City of San Francisco and was recognized as the "African Founding Father of California" by the California State Legislature in 2024. He is buried just inside the front doors of Mission Delores Basilica, San Francisco.

He never married and had no heirs. US Army Captain Joseph Folsom purchased his land grant and his San Francisco property from Leidesdorff’s St. Croix family. The purchase was considered quite controversial as Leidesdorff’s family was never informed of its true value and location in trajectory to the gold fields.

Today, the Landing at Leidesdorff in the San Francisco Financial District and Leidesdorff Plaza in the Folsom Historic District are the key West Coast anchors of our Leidesdorff Public Policy Research Center that is poised to share his great legacy with the world and help facilitate expanded California Pan African Global Trade and Investment opportunities.