Not the first Harley-Davidson motorcycle, but I believe this is credibly regarded as Harley-Davidson Serial Number One.
Fullsize image: https://s3-us-west-1.amazonaws.com/h...n_fullsize.jpg
https://s3-us-west-1.amazonaws.com/h...y_davidson.jpg
Previously:
https://www.homemadetools.net/forum/...638#post118121
https://www.homemadetools.net/forum/...477#post127786
https://www.homemadetools.net/forum/...117#post130210
https://www.homemadetools.net/forum/...448#post131745
https://www.homemadetools.net/forum/...944#post133745
https://www.homemadetools.net/forum/...596#post136304
https://www.homemadetools.net/forum/...873#post137314