Where is the serial number on a vintage hawthorne bicycle?

On a vintage Hawthorne bicycle, the serial number is typically located on the bottom bracket, which is the area where the pedals and crank assembly are attached to the frame. It may also be found on the rear dropout or near the head tube, depending on the model and year of manufacture. To locate it, you may need to clean the area, as paint and grime can obscure the number.