During the Civil War, it was not unusual for “camp followers” to accompany their men during a campaign. Wives, children and girlfriends were common in the field and they helped with cooking, laundry, etc.
I understand that General Hooker was known for being lax about camp followers, and the term “Hooker’s Women” arose because there were ... ahem ... more girlfriends than wives, so to speak.
At least, that’s the way I heard the origin of the word “hookers.”
Stars & Stripes has an interesting article on the origin of the term “hooker” in which at least partial credit is given to the General...