With the acquisition, the county owns the entire block except for a laundry and dry cleaning business. The block, directly across from the county jail, is crucial to the government's expansion plans.

The development plan, prepared by Charlotte's Freeman White Architects and unveiled last month, suggests a new school headquarters, a new federal courthouse, an additional county courthouse and a new office tower along East Fourth and East Trade streets. It also recommends street-level retail, trees and benches and possibly new entertainment zones.

The sale of the Fourth Street building and its nearly .6 acres of land was handled for the owner by MECA Properties' Jim Walsh and Rob Pressley. The county represented itself in the transaction.