Keywords: 1872 Chicago map by Mayer.jpg Map projected from a trigonometrical survey / and executed under the orders of Major C B Comstock Corps of Engineers ; and from local surveys made by J R Mayer J R Mayer 1872 http //collections lib uwm edu/cdm/singleitem/collection/agdm/id/1332/rec/7 UW Milwaukee Libraries PD-old map date 1872 Chicago 1 20 000 warp status United States Army Corps of Engineers print date 1872 accession number cm 71 61 other versions 1872 maps Old maps of Chicago Chicago in the 1870s |