S . ▁Route ▁ 6 6 , ▁which ▁opened ▁in ▁ 1 9 2 6 ▁with ▁its ▁eastern ▁termin us ▁in ▁the ▁area . ▁ ▁While ▁domin ated ▁by ▁offices ▁and ▁public ▁buildings , ▁its ▁resident ial ▁population ▁bo omed ▁during ▁the ▁latter ▁ 2 0 th ▁century ▁and ▁first ▁dec ades ▁of ▁the ▁ 2 1 st ; ▁its ▁population ▁has ▁increased ▁the ▁most ▁of ▁Chicago ' s ▁community ▁areas ▁since ▁ 1 9 5 0 . ▁ ▁History ▁ ▁Et ym ology ▁Some ▁believe ▁the ▁origin ▁of ▁the ▁term ▁Loop ▁is ▁derived ▁from ▁the ▁cable ▁car , ▁and ▁especially ▁those ▁of ▁two ▁lines ▁that ▁shared ▁a ▁loop , ▁constructed ▁in ▁ 1 8 8 2 , ▁bounded ▁by ▁Van ▁Bur en , ▁W ab ash , ▁Well s , ▁and ▁Lake . ▁ ▁Other ▁research ▁has ▁concluded ▁that ▁" the ▁Loop " ▁was ▁not ▁used ▁as ▁a ▁proper ▁n oun ▁until ▁after ▁the ▁ 1 8 9 5 – 9 7 ▁construction ▁of ▁the ▁Union ▁elev ated ▁railway ▁loop . ▁▁ 1 9 th ▁century ▁In ▁what ▁is ▁now ▁the ▁Loop , ▁on ▁the ▁south ▁bank ▁of ▁the ▁Chicago ▁River ▁near ▁today ' s ▁Michigan ▁Avenue ▁Bridge , ▁the ▁United ▁States ▁Army ▁ere cted ▁Fort ▁D ear born ▁in ▁ 1 8 0 3 , ▁the ▁first ▁settlement ▁in ▁the ▁area ▁spons ored ▁by ▁the ▁United ▁States . ▁When ▁Chicago ▁was ▁initially ▁pl atted ▁in ▁ 1 8 3 0 ▁by ▁the ▁survey or ▁James ▁Thompson , ▁it ▁included ▁what ▁is