U.S. Postal Service 6 Waelchli Ave, Halethorpe, MD21227 Neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed…More rounds through the greater Arbutus area. The U.S. Postal Service delivered the Hope Diamond, saved Santa Claus in "Miracle on 34th Street," and still delivers your handwritten note across the country for less than $1. A first-class letter is the last bargain in America.