▁is ▁no ▁section ▁of ▁SR   7 2 1 ▁that ▁is ▁included ▁within ▁the ▁National ▁Highway ▁System ▁( N HS ). ▁ ▁The ▁N HS ▁is ▁a ▁network ▁of ▁high ways ▁de emed ▁to ▁be ▁most ▁important ▁for ▁the ▁country ' s ▁economy , ▁mob ility ▁and ▁defense . ▁ ▁History ▁The ▁SR   7 2 1 ▁design ation ▁was ▁assigned ▁in ▁ 1 9 3 7 . ▁ ▁Through out ▁its ▁history , ▁the ▁route ▁has ▁maintained ▁the ▁same ▁alignment ▁in ▁the ▁general ▁vic inity ▁of ▁the ▁boundary ▁between ▁the ▁count ies ▁of ▁Dar ke ▁and ▁Miami . ▁ ▁Origin ally , ▁SR   7 2 1 ▁was ▁an ▁un p aved ▁road way ▁from ▁its ▁southern ▁termin us ▁at ▁SR   4 9 ▁to ▁its ▁j unction ▁with ▁US ▁ 3 6 . ▁ ▁The ▁portion ▁from ▁that ▁point ▁through ▁Brad ford ▁to ▁its ▁northern ▁termin us ▁at ▁SR   1 8 5 . ▁ ▁One ▁year ▁after ▁its ▁assignment , ▁SR   7 2 1 ▁was ▁p aved ▁between ▁SR   4 9 ▁and ▁Laura . ▁ ▁By ▁ 1 9 4 0 , ▁the ▁remaining ▁gra vel ▁portion ▁of ▁the ▁highway ▁between ▁Laura ▁and ▁US   3 6 ▁was ▁p aved . ▁ ▁Major ▁inter sections ▁ ▁References ▁▁ 7 2 1 ▁Category : Transport ation ▁in ▁Dar ke ▁County , ▁Ohio ▁Category : Transport ation ▁in ▁Miami ▁County , ▁Ohio <0x0A> </s> ▁M ixed ▁mart ial ▁arts ▁( M MA ) ▁is ▁a ▁form ▁of ▁compet itive ▁combat