Both were located along El Camino Viejo, modern 14th Street / State Route 185.
In the lower elevations of the city, an upper regionally contained aquifer is located 50 to 100 feet (15 to 30 m) below the surface.
The county seat was then re-established in the town of Brooklyn (now part of Oakland), California in 1872.
During the Civil War San Leandro and its neighbor, Brooklyn, fielded a California militia company, the Brooklyn Guard.
Contamination by gasoline, volatile organic compounds and some heavy metals has been recorded in a number of these lower elevation areas.
reported that San Leandro had a population of 84,950.
The population density was 5,423.8 people per square mile (2,094.1/km²).