▁Royal ist ▁Prop ri et ary ▁government . ▁ ▁In ▁William ▁P enn ' s ▁Frame ▁of ▁Government ▁of ▁ 1 6 8 2 , ▁he ▁established ▁a ▁combined ▁assembly ▁for ▁his ▁domain ▁by ▁providing ▁for ▁equal ▁membership ▁from ▁each ▁county ▁and ▁requiring ▁legisl ation ▁to ▁have ▁the ▁ass ent ▁of ▁both ▁the ▁Lower ▁Count ies ▁and ▁the ▁Upper ▁Count ies ▁of ▁Ch ester , ▁Philadelphia ▁and ▁Buck s . ▁The ▁assembly ▁meeting ▁place ▁altern ated ▁between ▁Philadelphia ▁and ▁New ▁Castle . ▁Once ▁Philadelphia ▁began ▁to ▁grow , ▁its ▁leaders ▁res ented ▁having ▁to ▁go ▁to ▁New ▁Castle ▁and ▁gain ▁agreement ▁of ▁the ▁assembly men ▁from ▁the ▁sp ars ely ▁populated ▁Lower ▁Count ies . ▁In ▁ 1 7 0 4 ▁members ▁of ▁the ▁two ▁regions ▁mut ually ▁agreed ▁to ▁meet ▁and ▁pass ▁laws ▁separately ▁from ▁then ▁on . ▁The ▁Lower ▁Count ies ▁did ▁continue ▁to ▁share ▁a ▁governor , ▁but ▁the ▁Province ▁of ▁Pennsylvania ▁never ▁merged ▁with ▁the ▁Lower ▁Count ies . ▁ ▁The ▁Mason – D ixon ▁line ▁forms ▁the ▁boundary ▁between ▁Del aware ▁and ▁Maryland ; ▁this ▁begins ▁at ▁the ▁Trans pen ins ular ▁Line . ▁The ▁border ▁between ▁Pennsylvania ▁and ▁Del aware ▁is ▁formed ▁by ▁an ▁arc ▁known ▁as ▁the ▁Tw elve - M ile ▁Circle ▁laid ▁out ▁in ▁the ▁sevent e enth ▁century ▁to ▁clearly ▁del ine ate ▁the ▁area ▁within ▁the ▁sphere ▁of ▁influence ▁of ▁New ▁Castle . ▁A ▁small ▁dispute ▁l inger ed ▁until ▁ 1 9 2 1 ▁over ▁an ▁area ▁known ▁as ▁the ▁W