Yep.

He was a subject of the British Empire. He spoke with a British accent. He fought for the British as an officer in the French & Indian Wars - meaning he commanded British troops.

His father was British. His grandfather went to school in Great Britain. His great-grandfather was born there. His ancestors were from Washington, Tyne & Wear in England. The ancestoral home — (which still exists) is Washington Old Hall (now a UK National Trust Property).

He never visited England but that wasn’t unusual in colonial days.

If the British had captured him before the general agreement around the Declaration of Independence, he would have been put on trial and almost certainly hanged as a traitor (they may have spared his wife).

Here is him in a British redcoat:

He was family friends with (and was once employed by) the only resident peer in late colonial America - Lord Fairfax.

He was a Freemason: An organisation focused around/originating in Great Britain.

He was a practicing member of the Church of England.

He lived longer being British than he did being American.

The concepts of "natural law" and "inalienable rights" used by the American Founding Fathers were not valid at the time under any law, anywhere.