The only suggestion I have is to look up each territory in Wikipedia, find its area and use one of them new-fangled calculatorium thingamajigs to add them all up.
I expect you to be using roods and perches, no?
I can't see why not.
The weights, measurements and currencies varied from colony to colony and were not standardised until 1866. And a rood is as near as makes no difference 1000 square metres, so I would be pretty much cutting edge something or other were I to use such measurements.
Many thanks Jill. I am a bit cautious about using a map because they are Mecator projections and the top bits don't correspond to the bottom, but I reckon that is going to be the best I can get so once again, many thanks.
Bernard Cornwell made the point that one of the reasons that the Americans won the War of Independence was that the place was so big. The British army often won the battles but the Yanks said so what? There was always more land and the only bit the Redcoats had was the bit they were standing on.
But the expansion of early America has always fascinated me. They were always desperate for more land although they often did not have enough people to settle it. In 1812 the US made the invasion of Canada one of its war aims. Not only did the Americans not have enough troops, they weren't really sure where the place was, but that did not stop them.