▁ ▁Chron ology ▁The ▁history ▁of ▁S pi ro ▁is ▁typically ▁divided ▁into ▁arch ae ological ▁phases : ▁ ▁Evans ▁Ph ase ▁( 9 0 0 – 1 0 5 0 ▁CE ) ▁ ▁Har lan ▁Ph ase ▁( 1 0 5 0 – 1 2 5 0 ▁CE ) ▁ ▁Norman ▁Ph ase ▁( 1 2 5 0 – 1 3 5 0 ▁CE ) ▁ ▁S pi ro ▁phase ▁( 1 3 5 0 – 1 4 5 0 ▁CE ) ▁ ▁Res ident ial ▁construction ▁at ▁S pi ro ▁decre ased ▁dram atically ▁around ▁ 1 2 5 0 , ▁and ▁people ▁settled ▁in ▁nearby ▁villages , ▁such ▁as ▁the ▁Cho ates - H olt ▁Site ▁to ▁the ▁north . ▁S pi ro ▁was ▁used ▁as ▁a ▁cer emon ial ▁and ▁mort u ary ▁center ▁through ▁ 1 4 5 0 . ▁The ▁m ound ▁area ▁was ▁abandoned ▁about ▁ 1 4 5 0 , ▁although ▁nearby ▁communities ▁pers isted ▁until ▁ 1 6 0 0 . ▁The ▁cult ures ▁following ▁in ▁the ▁w ake ▁of ▁S pi ro ▁were ▁less ▁complex ▁and ▁hier arch ical . ▁ ▁M ounds ▁and ▁pla za ▁area ▁ ▁Mississ ipp ian ▁culture ▁spread ▁along ▁the ▁lower ▁Mississippi ▁River ▁and ▁its ▁trib ut aries ▁between ▁the ▁ 9 th ▁and ▁ 1 6 th ▁centuries . ▁The ▁largest ▁Mississ ipp ian ▁settlement ▁was ▁C ah ok ia , ▁the ▁capital ▁of ▁a ▁major ▁chief dom ▁that ▁built ▁a ▁six - mile - square ▁city