who led the first overland expedition to san diego
Portolá expedition Captain Fernando Rivera, moving north through Baja California, gathered horses and mules from the fragile chain of Catholic missions to supply his overland expedition. José de Gálvez had ordered Rivera to requisition horses and mules from the missions without endangering their survival and give the friars receipts for the number of animals taken; those missions would later get restocked with animals brought over from the Mexican mainland. Friar Juan Crespí, selected as chaplain for the Rivera party and diarist for the Franciscan missionaries, traveled 24 days from Mission La Purísima, 400 miles (640 km) north to Velicatá (near the current town of Ramona), then the northern frontier of Spanish settlement in Baja California. There Crespí met up with the Rivera party, which set out from Velicatá on March 24. Their mule and horse train, tended by three muleteers, carried 25 leather-jacket soldiers and 42 Baja California Christian Indians (all men).[7]
Mexican–American War In the Winter of 1845–46, the federally commissioned explorer John C. Frémont and a group of armed men appeared in Alta California. After telling the Mexican governor and the American Consul Larkin he was merely buying supplies on the way to Oregon, he instead went to the populated area of California and visited Santa Cruz and the Salinas Valley, explaining he had been looking for a seaside home for his mother.[22] Mexican authorities became alarmed and ordered him to leave. Frémont responded by building a fort on Gavilan Peak and raising the American flag. Larkin sent word that Frémont's actions were counterproductive. Frémont left California in March but returned to California and took control of the California Battalion following the outbreak of the Bear Flag Revolt in Sonoma.[23]