▁Cur ving ▁to ▁the ▁east , ▁the ▁highway ▁cross es ▁I - 2 8 5 ▁and ▁reaches ▁its ▁eastern ▁termin us ▁at ▁the ▁western ▁edge ▁of ▁H arts field – Jack son ▁Atlanta ▁International ▁Airport ▁in ▁College ▁Park . ▁ ▁The ▁entire ▁length ▁of ▁SR   6 ▁is ▁part ▁of ▁the ▁National ▁Highway ▁System , ▁a ▁system ▁of ▁routes ▁determined ▁to ▁be ▁the ▁most ▁important ▁for ▁the ▁nation ' s ▁economy , ▁mob ility , ▁and ▁defense . ▁ ▁History ▁SR   6 ▁was ▁established ▁at ▁least ▁as ▁early ▁as ▁ 1 9 1 9 ▁from ▁SR   1 ▁in ▁C ed art own ▁east - s out heast ▁through ▁Dallas ▁to ▁SR   8 ▁in ▁Aust ell . ▁By ▁the ▁end ▁of ▁September ▁ 1 9 2 1 , ▁it ▁was ▁extended ▁west ward ▁to ▁the ▁Alabama ▁state ▁line . ▁By ▁October ▁ 1 9 2 6 , ▁US   7 8 ▁was ▁designated ▁on ▁SR   8 ▁at ▁SR   6 ' s ▁eastern ▁termin us . ▁About ▁ 2 0 ▁years ▁later , ▁between ▁the ▁beginning ▁of ▁ 1 9 4 5 ▁and ▁November ▁ 1 9 4 6 , ▁the ▁entire ▁segment ▁from ▁Alabama ▁to ▁Aust ell ▁was ▁hard ▁sur fac ed . ▁Between ▁June ▁ 1 9 5 4 ▁and ▁June ▁ 1 9 5 5 , ▁US   2 7 8 ▁was ▁designated ▁on ▁the ▁entire ▁original ▁segment . ▁Between ▁June ▁ 1 9 6 3 ▁and ▁the ▁end ▁of ▁ 1 9 6 5 , ▁SR