▁professional ▁champions , ▁were ▁usually ▁then ▁claimed ▁by ▁the ▁teams ▁from ▁Ohio . ▁Though ▁a ▁champion ▁was ▁declared ▁by ▁the ▁media , ▁fans ▁and ▁clubs ▁throughout ▁this ▁period , ▁a ▁formal ▁league ▁was ▁not ▁founded ▁until ▁ 1 9 2 0 , ▁when ▁several ▁teams ▁from ▁the ▁" Oh io ▁League " ▁and ▁the ▁New ▁York ▁Pro ▁Football ▁League ▁formed ▁the ▁American ▁Professional ▁Football ▁Association . ▁In ▁ 1 9 2 2 ▁the ▁AP FA ▁became ▁the ▁National ▁Football ▁League . ▁ ▁The ▁circuit ▁did ▁not ▁immediately ▁die ▁out ▁and ▁in ▁fact ▁experienced ▁a ▁slight ▁r ena issance ▁in ▁the ▁ 1 9 2 0 s ▁as ▁the ▁Western ▁Pennsylvania ▁Senior ▁Independent ▁Football ▁Conference . ▁ 1 9 2 0 s ▁era ▁blue ▁laws ▁in ▁the ▁state ▁of ▁Pennsylvania ▁meant ▁that ▁while ▁the ▁NFL ▁played ▁its ▁games ▁on ▁Sunday , ▁Pennsylvania ▁teams ▁would ▁have ▁to ▁play ▁on ▁Saturday ; ▁while ▁this ▁prevent ed ▁the ▁state ' s ▁teams ▁from ▁joining ▁the ▁NFL ▁until ▁ 1 9 2 4 , ▁Pennsylvania ▁teams ▁could ▁thus ▁schedule ▁exhibition ▁games ▁against ▁NFL ▁teams ▁on ▁either ▁one ' s ▁day ▁off ▁( other ▁circ uits ▁such ▁as ▁the ▁eastern ▁Pennsylvania ▁circuit ▁and ▁the ▁Eastern / An th rac ite ▁Le agues ▁also ▁th riv ed ▁in ▁the ▁ 1 9 2 0 s ) ▁The ▁J . P . ▁Ro one ys ▁were ▁founded ▁in ▁ 1 9 2 1 ; ▁it ▁later ▁joined ▁the ▁NFL ▁in ▁ 1 9 3 3 ▁as ▁the ▁Pitts burgh ▁Pir ates