The title longshoreman goes back to a time when there was very little mechanical help to unload a great sailing vessel, and often there were no port or docking facilities either.
Everything was done by hand.
Unloading the big ship into smaller rowing boats, then unloading these onto the shore, was hard work and needed a lot of strong men.
Because these men would line up on the water’s edge, they were called “along the shore men” which in time became simply “longshoremen.”
The word stevedore came from Spain or Portugal, and entered the English language through its use by sailors.
It started as a phonetic spelling of the Spanish word “estibador”, meaning a man who stuffs.
But the common meaning of stevedore is a man who loads ships.