The photos are mostly from a shoot of March 1943 on Santa Fe freight trains pulled by steam locomotives between Chicago and Los Angeles. As captions note, there are one each from January and April on the Chicago and North Western Line.
In all cases the photographer was Jack Delano and the assignment came from the Information Division of the Farm Security Administration unit in the Office of War Information.
All the photos come from the Farm Security Administration/Office of War Information Collection in the Library of Congress Prints and Photos Division. The captions are from notations on the film negatives and were prepared by P&P staff members. Click to view full size.
For more information, see my previous posts of Jack Delano's railroad photos here and here.
Although growing numbers of women were entering the workforce in 1943, there were relatively few women in railroad jobs and those who had them mainly did yard work. Their numbers would grow during the rest of World War II, but there's no record (that I can find) of women riding the caboose or elsewhere in the freight trains themselves. Although many male railroad workers served in the armed forces, local draft boards could and routinely did give deferments to men in this occupation.
Some sources on this topic:
Women railroad workers: