In the early days of motorcycling sidecars were extremely popular. Illustrations show both male and female passengers. There were sidecars made to fit certain makes and models and universal sidecars said to fit on just about any bike. Below is an ad from 1913 about a sidecar built by Hendee specifically for Indians.
Of Hendee manufacture throughout is the Indian sidecar with underslung chassis and all-metal body of the side-entrance type. The framing is of staunch tubing and double trussed with three connections to the motorcycle. The sidecar wheel is not sprung but, as fitted to an Indian motorcycle, the outfit is in fine balance, enabling the rider to run “hands off” and rendering steering of the outfit remarkably easy. The body has a side door and is most comfortable, having ample leg room and seat space for the passenger. It is upholstered in black leather and the general color is Indian red with this exception. The mudguard is five inches wide and is provided with a cowl at the side and front, being attached to the body instead of the frame. The equipment includes storm aprons and a foot mat, and a tool-box is fitted in the body under the removable seat.
Source: “Motorcycle Illustrated”. 1913.