Photographer Jack Delano spent some time in the rail yards of Chicago 75 years ago picturing workers who kept the trains running and almost everything that’s connected to this world. Today, some of his most striking pictures are preserved in the Library of Congress.

Check them out for more information and start to see our world through photos!

A view of part of the South Water Street freight depot of the Illinois Central Railroad and buildings in downtown Chicago on May 1, 1943

Jack Delano / Library of Congress

In the roundhouse of a Chicago and North Western Railroad yard in December 1942

Jack Delano / Library of Congress

A view of part of the South Water Street Illinois Central Railroad freight terminal in April 1943

Jack Delano / Library of Congress

A switchman throwing a switch at Chicago and North Western Railroad’s Proviso yard in April 1943

Jack Delano / Library of Congress

A welder works in the roundhouse of the Chicago and North Western Railroad’s Proviso yard in December 1942.

Jack Delano / Library of Congress

Mike Evans, a welder, at the rip tracks at the Proviso yard, photographed in April 1943

Jack Delano / Library of Congress

Working on a locomotive at the 40th Street railroad shops in Chicago in December 1942

Jack Delano / Library of Congress

Illinois Central Railroad freight cars at the South Water Street freight terminal in Chicago in April 1943

Jack Delano / Library of Congress

The night is lit up by a giant Pabst Blue Ribbon sign above Chicago’s South Water Street freight terminal in April 1943.

Jack Delano / Library of Congress