Dover, Delaware: From the town in England of that name. The Anglo-Saxon word means "ferry."
[A correspondent writes: Dover - This is where I was born (the one in England). It is not likely that the name derives from the Saxon word for ferry. The town's name predates the arrival of the Saxons by a few centuries. The Romans applied a Latinized name of Dubris when they arrived in the town, which is equivalent to the much later French name Douvres, which anglicizes to to Dover. Note that the Dour River flows through Dover. Exactly what variation of Dover was used before the Romans arrived is presumably lost.]