Where did term bus boy come from?

Answer 1

In the late 19th century, busboys were originally known as "omnibuses", a term which came from the Latin "omnibus," meaning "for all." "Omnibus" was a popular word in the 19th century with a variety of uses, having first been applied to the large public horse-drawn coaches which marked the first appearance of urban mass transit. The motorized descendants of these omnibuses are known today, of course, as "buses."

While busboys of the period may or may not have ridden to work on buses, they were known as "omnibus boys" or "omnibuses" themselves because their job was to do anything and everything that might be useful in the restaurant. "Omnibus" in this restaurant sense first appeared in 1888, and the first written example of the shortened form "bus-boy" has been traced to a 1913 issue of "The Industrial Worker" although the word was almost certainly in use long before then.