Stearns quickly understood the importance of a port to Los Angeles. He obtained from the city council (Ayuntamiento) a concession to build a warehouse in San Pedro. He was soon writing letters urging the annexation of the port by the pueblo.
He established a stage route connecting San Pedro with Los Angeles, at ten dollars per person; freight was also ten dollars a ton.
He married into the wealthy Bandini family, and in 1840 bought the huge Rancho Los Alamitos. Along with John Temple they were the largest landowners in the area.
However, there was a drought between 1862 and 1864 which was said to have resulted in the death of 50,000 cattle on Stearn's land alone. Both he and Temple first mortgaged and then sold their property to John Bixby, who by 1878 owned all of what is now Long Beach.