The same ancestors, same language, same customs, same religion, same principles of government?
Just taking British colonies alone and forgetting the multiple stakes claimed and influx of labour from yet more countries to do the actual building for dominant political powers that treated them like vermin you've got an ethnic mix of Angles, Saxons, Frisians, Normans, sub groups of Celts such as Gauls, Welsh, etc. All with disparate customs and language though English eventually supplanted them. And American English is distinct enough to merit a completely different language setting on your computer from Canada and Britain.
Also you drive on the opposite side of the road just to be different, the same reason you cling to imperial measurement when the world adopted metric.
And government? You realize your Founding Fathers whole deal and the entire formation of the American government were as a rejection of the monarchy you came from? And that even today your states are fiercely adamant about setting their own individual constitutions, laws, and procedures?
Religion? Oh holy shit how can you think there's any such thing as a unified religion anywhere on this Earth let alone a country that romanticizes pilgrims fleeing religious persecution at home which had a vicious schism between Catholicism and Protestants only to impose their own views by violence and subdivide into factions that denounce each other from Evangelicals, to Mormons, to Baptists, to WBC?
Your John Jay is a clueless gobshite. And if you don't know what that means I refer you back to the rebuttal about common language. The most generous interpretation would be that he saw that as being true going forward, but it still fails to account for further immigrants - yes even the white ones - and existing religious divisions that Constitutionally the government would not abolish or adopt/enforce... Well, except that Christianity wormed its way into government regardless of that little detail.
You're looking anywhere but the present, not to strengthen your country but for excuses to claim it as a personal playpen and demand tribute from those within for the privilege of your presence. And the tribute itself you claim as your own achievement, leverage for further tribute. Nobody does more to devalue and destabilize "white culture" than white supremacists. Just look at your own ignorance of, disrespect for, and in many cases a complete willingness to knowingly rewrite your own history with the rise and collapse of the Confederacy rebranded as "Northern Aggression" as a prime example. Look at the Capitol Hill insurrection and the literal defecation upon the symbol of the will of the American majority and unified value of law that the mob which repeatedly adorns itself with white supremacist symbols and race rhetoric performed.