In 1932 several states didn’t have maps in place and elected all their members at-large, as the map you blogged shows.
https://upload.wikimedia.org/wikipedia/commons/4/4a/1932_House_Election_in_the_United_States.png
This resulted in MO and KY sending no Republicans to the House, for the first time since 1890 and 1878, respectively. It was the last time either state elected an all-rat delegation.
Notice the two Republican districts in East Tennessee the mountain people didn’t support the Confederacy. They voted Republican ever since the Civil War Era..
States no longer have the option of electing House members at-large (Baker v. Carr).
