William Alexander Leidesdorff, Jr. (October 23, 1810 – May 18, 1848) was one of the earliest biracial-black U.S. citizens in California and one of the founders of the city that became San Francisco. A highly successful, enterprising businessman, he was a West Indian immigrant of African Cuban, possibly Carib, Danish/Swedish and Jewish ancestry. Leidesdorff became a United States citizen in New Orleans in 1834. He migrated to Alta California in 1841, then under Mexican rule, settling in Yerba Buena (now San Francisco), a village of about 30 Mexican and European families. He became a Mexican citizen in 1844 and received a land grant from the Mexican government, 8 Spanish leagues, or south of the American River, known as Rancho Rio de los Americanos. He served as US Vice Consul to Mexico at the Port of San Francisco beginning in 1845. Leidesdorff was President of the San Francisco school board and also elected as City Treasurer. Shortly before Leidesdorff's death, vast amounts of gold were officially reported on his Rancho Rio De los Americanos. By the time his estate was auctioned off in 1856, it was worth more than $1,445,000, not including vast quantities of gold mined upon his land. International Leidesdorff Bicentennial Celebrations featured the "Golden Legacy of William Alexander Leidesdorff, Jr." On October 22, 2011 on his native isle of Saint Croix, U.S. Virgin Islands, a special event was to highlight the season of celebrations. Early life Born in Christiansted in Saint Croix when the Virgin Islands were under Danish rule (Danish West Indies), William Leidesdorff, Jr. was the oldest son of four children of Danish sugar plantation manager Wilhelm Alexander Leidesdorff (who used Alexander Leidesdorff as his name) and his common-law wife Anna Marie Sparks, reportedly of African and Spanish descent. Wilhelm Leidesdorff Sr. was reportedly of Jewish descent from the community of Altona, Hamburg. It was part of the Danish Schleswig-Holstein, then across the river from but now part of today's port of Hamburg, Germany. He migrated to North America and later the Caribbean to further his career as a merchant. Leidesdorff and Anna Marie lived in New Orleans under Spanish rule before the Louisiana Purchase, and he worked as a sugar factor. Leidesdorff, Jr.'s mother Anna Marie Sparks, was described in one account as a Carib Indian woman; she was believed also to have had African and European ancestry. Her race was noted in a census