You may not be familiar with military slang, the word mustang in the U.S. Navy broadly means an officer who has has risen through the enlisted ratings to become an officer. Navy lore suggests old seahorses rise through the ratings to become mustang officers. Others suggest mustangs are wild, roaming the range acquiring knowledge on how to survive in the wild and when they become officers, they bring knowledge the military academies do not teach. There is the belief that seahorses carried the souls of deceased sailors to the underworld - giving them safe passage and protection until they met their soul's destination and that the mustangs would look after them in this world.
There is a common saying around the Navy, that a Navy wife has two husbands, one is that nice young sailor she had married those many years ago and the other is the more demanding one, the US Navy.
The Navy liked to move the fleet from the east coast to the other for a year or so then transfer them back to the east coast in the name of national preparedness. Consequently, the families moved with them. Those whose husbands had a good enlisted rating or were married to officers might travel by train for almost a week or they might take a steamship through the Panama Canal and on to San Diego, Mare Island near San Francisco, or perhaps to Seattle, Wa. Shipping the family car was out of the question so many elected to drive the 3000 miles from one coast to the other rather than selling it. It was not unusual to pack those household essentials in the back seat of the family car and drive to the new duty station.
Louise and Peggy were young navy wives who were driving to Charleston, SC to join their sailor husbands and had decided to visit Peggy's parents in Alabama. Here's a exerpt from one of their crosscountry trips One Day In Alabama In 1934