Were early balloons really made from animal guts?

Why do we blow up balloons at parties? What gas was originally used to make balloons float? What else are balloons used for? For free home activities sign-up at www.WhoSmarted.com       See omnystudio.com/listener for privacy information. See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.