Roedd o leiaf bump o’r rhai a lofnododd y Datganiad Annibyniaeth yn Gymry neu o dras Cymreig diweddar. Roedd gan o leiaf wyth o gyn Arlywyddion yr Unol Daleithiau wreiddiau Cymreig, gan gynnwys Thomas Jefferson, Abraham Lincoln, John Adams a John Quincy Adams.
At least 5 of the signatories of the Declaration of Independence were Welsh or of recent Welsh descent, and there have been at least 8 US Presidents with Welsh ancestry, including Thomas Jefferson, Abraham Lincoln, John Adams and John Quincy Adams.