The city of Oakland is made up of a large number of smaller communities that were either annexed or absorbed by the city's growth and development. Many of the neighborhood names that still exist, such as Temescal, Clinton, Brooklyn, Piedmont, Claremont, etc., are legacies of the original independent cities that sprouted up all over the East Bay once settlers started moving in beginning in the late 1840s. Brooklyn is one of the more historically important communities that was absorbed into Oakland proper. Comprising most of what is today considered East Oakland, Brooklyn began on the south side of the San Antonio River and extended East to the hills and south to the San Leandro border. There's a neat historic map off the area that you can see here if you're interested.
Brooklyn came into being when two smaller preexisting communities, San Antonio and Clinton, amalgamated in 1856, four years after the incorporation of the City of Oakland. Brooklyn continued to develop and absorbed the neighboring city of Lynn in 1870. In 1872 the residents of Brooklyn voted for annexation by the city of Oakland.
The remains of downtown Brooklyn are still standing on E. 12th St., between 11th and 12th Ave. This row of buildings dates to at least the 1870s, but there's been a great deal of renovation and reconstruction so it's difficult to claim that these buildings are truly historic any longer.
Brooklyn and Oakland were the two largest communities in the East Bay, at least initially, and they were sister cities whose borders meet at the San Antonio River and the opposite shores of Lake Merritt. The need to travel between the two cities led to the creation of a toll bridge at what is now 12th St. The bridge was built and controlled by Horace Carpentier, an East Bay lawyer who was responsible for a whole host of shady dealings, including fleecing hundreds of acres of land off of the Peralta family, original holders of the Rancho San Antonio and most of the land in the East Bay, by representing them in federal court and accepting land grants as payment. He also controlled the Oakland waterfront through semi-legal back room deals, and was the primary mover behind the incorporation of the City of Oakland, which was, at least initially, accomplished to suit his political and personal goals and was pursued largely without the consent of the residents of the city. The toll bridge that Carpentier built was tremendously unpopular and was a site of populist unrest, including community rushing of the toll booth, boycotts, and the creation of competing bridges. The toll bridge was finally removed when Samuel Merritt, the mayor of Oakland, donated the land and the money to create both Lake Merritt and the 12th St. bridge and dam.
Getting There By Bike...
It's probably easiest if you take 12th St. straight south from downtown Oakland. The buildings are located between 11th and 12th Aves on the east side o the street. There's a whole host of Korean businesses in the buildings now and it's kind of neat to think about how this community has changed over the years and has been made to meet the needs of whatever people are living here.