Madison
In his travel account Ralph Colin Ross states that the Ross family left Chicago for their cross-country trip during a snowstorm. Assuming that this was in January, after Ross had fulfilled a number of speaking engagements there,1-2 it is plausible that they drove from Chicago northwards through snow-covered Madison, WI, and from there, joined US Route 16 via Watertown to Milwaukee, WI, and continued by ferry to Michigan, in early January 1939.
Colin Ross. Amerika Reise - Zwischen Ostküste und Wisconsin [archive title]
Germany. Tobis; 1938-1939
35mm | b&w | silent | 310m | 16 fps | 17’
Master: 0003-02-0120_Amerika_Reise_Washington_X_OeFM_2016_PR422HQ_3072x2160_24fps.mov; 00:06:00,00–00:06:04,17
Clip:0003-02-0120_Amerika_Reise_Washington_X_OeFM_2016_H264-12Mbits-KFauto-CABAC_1440x1080_16fps_IsFormatOf_ProRes422_3072x2160_24fps_00060000-00060417.mp4
Footnotes
1 Ralph Colin Ross. Von Chicago nach Chungking. Einem jungen Deutschen erschließt sich die Welt. Berlin: Die Heimbücherei, John Jahr; 1941: 57. See Library.
2 Bodo-Michael Baumunk. Colin Ross. Ein deutscher Revolutionär und Reisender 1885-1945. [unpublished master’s thesis]. rev. edn. Berlin; 2015 [1999]: 106. See Library.