Public domain
The track between Pequot, Illinois and Fort Madison, Iowa is governed by automatic train control. This is one of the relay boxes. The number "1051" stands for the first relay box in the 105th mile from Chicago
From the collection of Library of Congress. Free to download, adapt and use — no permission needed.
Credit lineThe track between Pequot, Illinois and Fort Madison, Iowa is governed by automatic train control. This is one of the relay boxes. The number "1051" stands for the first relay box in the 105th mile fro. 1943-01-01. Delano, Jack. Farm Security Administration/Office of War Information Collection, Library of Congress. Public domain.