why do they call them "slumber parties"?

i understand the "party" part, but "slumber" implies that there will be sleep involved and no one actually gets any sleep - not the kids and not the parents! last night my hubby was out of town on a fishing trip so i decided to have a sleepover with some friends. i have been friends with my friend teresa since i moved here in the 7th grade (22 years ago)! (please don't do the math!) teresa's oldest daughter is in school with my kindergarten and they are best friends. teresa also has another daughter that is one year older than my baby. so the four girls and teresa and i all went to eat at taco casa and then came home and did crafts and ate junk food and drank "kid wine" (sparkling grape juice). we made a palette on the floor for them and put a movie on and let them go to sleep watching it. teresa and i stayed up talking until almost 2 in the morning and then were woken up by little ones a little after 7 in the morning!! we made breakfast this morning (muffins for the kids and breakfast tacos for the moms) and let the girls play outside together. it has been so many years since teresa and i had spent the night together and now to do it again with our kids was really fun but needless to say we all needed naps today!