▁ 1 7 8 0 , ▁nearly ▁double d ▁again ▁by ▁ 1 7 9 0 , ▁and ▁nearly ▁triple d ▁once ▁more ▁by ▁ 1 8 0 0 ." ▁ ▁Mar anh ão ▁did ▁not ▁join ▁in ▁the ▁Brazil ian ▁declaration ▁of ▁independence ▁of ▁ 1 8 2 2 , ▁but ▁in ▁the ▁following ▁year ▁the ▁Portuguese ▁were ▁driven ▁out ▁by ▁British ▁sail or ▁and ▁liber ator ▁Admir al ▁Lord ▁C och rane ▁and ▁it ▁became ▁part ▁of ▁the ▁Empire ▁of ▁Brazil . ▁For ▁this ▁achiev ement ▁Lord ▁C och rane ▁became ▁ 1 st ▁Mar ques ▁of ▁Mar anh ão ▁and ▁Governor ▁of ▁Mar anh ão ▁Province . ▁ ▁São ▁Lu ís ▁is ▁the ▁Brazil ian ▁state ▁capital ▁which ▁most ▁closely ▁res emb les ▁a ▁Portuguese ▁city . ▁By ▁the ▁early ▁ 2 0 th ▁century ▁São ▁Lu ís ▁had ▁about ▁ 3 0 , 0 0 0 ▁inhabitants , ▁and ▁contained ▁several ▁convent s , ▁char itable ▁instit utes , ▁the ▁epis cop al ▁palace , ▁a ▁fine ▁Car mel ite ▁church , ▁and ▁an ▁ecc les iast ical ▁sem inary . ▁The ▁historic ▁city ▁center ▁was ▁declared ▁a ▁World ▁Heritage ▁Site ▁in ▁ 1 9 9 7 . S ão ▁Lu ís , ▁Mar anh ão ▁ ▁Dem ograph ics ▁ ▁According ▁to ▁the ▁IB GE , ▁there ▁were ▁ 6 , 4 0 0 , 0 0 0 ▁people ▁res iding ▁in ▁the ▁state ▁in ▁ 2 0 0 8 . ▁The ▁population ▁density ▁was ▁ 1 8