From a 1945 copy online of Statistics of Class 1 Motor Carriers from The Interstate Commerce Commission. This list represents the largest trucking companies based in the mid-western region of the United States based on annual revenues which are listed beside the name of the carrier.

1-Watson Bros. Transportation Co. Inc. $3,856,179

2-Denver-Chicago Trucking Co. Inc. $2,585,864

3-Union Freightways $2,243,297

4-Merchants Motor Freight, Inc. $1,612,538

5-Brady Motor Service Co. $1,427,013

6-Anderson Motor Service Co. $1,379,342

7-Riss & Co. Inc $1,373,432

8-Campbell Sixty-Six Express Inc $ 1,079,424

9-Knaus Truck Line $832, 171

10-Mid-States Freight Lines, Inc. $785,192

11-Be-Mac Transport Co. Inc. $764,979

12-H&W Motor Express Co. $715,675

13-Orscheim Bros. Truck Lines, Inc. $617,930

14-Byers Transportation Inc.$619,807

15-Western Transportation Co. $601,172

16-Red Ball Transfer Co. $558,810

17-Adams Transfer & Storage Co. $ 508,377

18-Des Moines Transportation Co. Inc, $ 501,961