Roma owes much of the credit for its distinctive architecture to one man: Heinrich Portscheller. Portscheller’s design was deeply influenced by Mexico – his home after leaving Germany. The structures he built in Roma and across the Rio Grande Valley took on a distinct styling influenced by Mexican architecture — particularly that of Matamoros, which was a cosmopolitan mercantile center influenced itself by Creole New Orleans.
Roma contains the largest surviving concentration of Portscheller's work in Texas. Examples of his work here include the Manuel Guerra House and Store, constructed between 1878 and 1884; the Antonia Sáenz House; the Tino Ramirez Residence and Store; and the Old Roma Convent, a one-story brick building constructed circa 1880.