Poinsett County Arkansas (Historic Districts) has 6 places on the National Register of Historic Places including 2 places of National significance. Significant places include Marked Tree Lock and Siphons and Tyronza Commercial Historic District, Harrisburg Commercial Historic District, Highway A-7, Bridges Historic District and Lepanto Commercial Historic District.
Some of the country's most noteable architects helped create the Poinsett County places including US Army Corps of Engineers, H.A. Lesmeister, V.W. Clanton, Mitchell Selligman, Riherd, Leslie and Rev.. Prominent architectural styles found in Poinsett Country are Early Commercial, Classical Revival and Art Deco.