The Downtown Historic District, Inc (DHD) is a non-profit organization, founded in 1991, that serves as an advocate for the preservation and redevelopment of the Main Street / Market Square Historic District in downtown Houston. The Historic District rests between Buffalo Bayou, Minute Maid Park, Houston’s Theater District, and some of the world’s tallest and finest skyscrapers. The District comprises most of the original town plat of Houston as it was laid out by Augustus Chapman Allen and John Kirby Allen, Houston’s founding brothers, in 1836. Special emphasis is given to the renovation and restoration of historic structures. The area was listed in the National Register of Historic Places in 1983 and declared a City of Houston Historic District in 1997.