I always thought that Dartmouth was the British version of Westpoint. The British officer training school, but now in my googling it seems Google assumes I'm searching for the US university. I was wondering what the relationship with the two Dartmouths were?
Lots of places in America are named after places in the UK. See the York that made the New York new. As I understand it was common for groups of colonists to name places in the 'New World' after places they came from.
Pretty much every place name in Britain seems to appear in the US somewhere. Dartmouth is a region of Devon, where I happen to live. Literally 'The mouth of the river Dart' which runs from Dartmoor through Paignton. With Devon having quite large ports nearby (Plymouth) and also being on that side of the country, it was a convenient place to launch colonial ships.
There are also Dartmouths in Australia and Canada. https://geotargit.com/called.php?qcity=Dartmouth