Biographical Info provided by fellow Graver,Sheila Ruiz Harrell - thank you!
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"Juan María Osuna was born 1785 in California to Theodoso Osuna (from Spain) and Luguarda Quisques (Indian)." but in the marriage entry, Mission San Diego Marriage Register, Entry #00818, 15 Feb 1806 Juan Osuna is listed as the son of Juan Osuna (difuntos) and Maria Ygnacia Alvarado (difuntos)and is marrying Maria Juliana Lopez. This marriage entry can be sourced as [SC Marriage 00818 ECPP]. ECPP is the Early California Population Project database available online. In the 1790 Census this Juan Maria Osuna is listed with his mother Maria Ignacia Alvarado, a widow, living with her four children at Los Angeles.
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Wikipedia Bio
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Juan María Osuna was born 1785 in California to Theodoso Osuna (from Spain) and Luguarda Quisques (Indian). He was a soldier and corporal of the San Diego Company and settled in San Diego. Osuana was District elector in 1830 and took part in the Mexican Revolution of 1831.

After retiring as a corporal, Osuna and his family were the first to build on the plain outside the Presidio of San Diego. He built a three-room adobe with his sons and a dispensary.

In 1833, with five other male citizens, Osuna urged the governor to establish a pueblo (town) government for San Diego, to replace 60-some years of military rule. On January 1, 1835, this came to reality and Osuna was elected the first Alcade of San Diego pueblo. Lt. Santiago Argüello, the last Commandant of San Diego Presidio gave Osuna his staff of office, symbolizing the transfer of government from the military to civilian self-rule. He defeated Pío Pico by 13 votes. Pico later became the last Mexican governor of Alta California. Osuna also served as juez de pas (justice of the peace) 1839–40 and 1846.

On February 15, 1806 Osuna married María Juliana Josepha Lopez, who was born March 16, 1791 to Juan Francisco Lopez, of the Portolà Expedition) and María Feliciana Arballo de Gutierrez. Their daughter Felipa married Juan María Marrón, daughter Luguarda married José María Alvarado, and their two sons were Leandro and Ramon.

Osuana was granted Rancho San Dieguito, 25 miles (40 km.) north of San Diego along the coast, during 1836–1845. He raised cattle and horses on the ranch. Osuna had a weakness in gambling and had to sell some of his land to pay off his debts. Today Rancho San Dieguito is known as Rancho Santa Fe, an exclusive residential area. Osuana's adobe, overlooking the San Dieguito River Valley, has been restored and is part of The Inn at Rancho Santa Fe.

During the Mexican-American War Osuna remained loyal to Mexico. In 1846, U.S. troops occupied his San Diego home and his youngest son Santiago was killed. His last years were difficult under U.S. rule as he didn't speak English and was unfamiliar with U.S. law and customs.

Osuna died 1851. He is buried in El Campo Santo Catholic Cemetery in Old Town San Diego. A modern headstone reads "JUAN MARIA OSUNA DIED 1851 FIRST ALCALDE OF SAN DIEGO". His wife died December 22, 1871 and was buried next to him.
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