Quite an interesting question. methinks that jumping from revolution to civil war, let alone to WW1, is a bit to far as the events that really "made" America were before the civil war.
The Louisiana purchase (to help Nappy finance his war in Europe) effectively doubled the size of the U.S. in 1803. The Russians still owned Alaska and had settlement's as far south as FT Ross CA. Mexico, Spain, France, whomever was in control today, claimed most of the southwest and CA up to San Francisco up until 1853 when the Texas revolution, Gadsden purchase, and Mexican cession, 1845 to 1853 added another million sq. miles to the U.S. territory.
It seems to me that France would not have "sold" the French American territory to the British let alone that they would buy it to help finance a war against themselves.
Now without most of the northwest, and everything west of the Mississippi, even had the Texas revolution been successful (no U.S. help). Would Britain have declared war on Mexico and had them cede Arizona, New Mexico, Southern Colorado, California (south of San Francisco) and parts of Utah and Nevada? And we still have not resolved the Spanish claim in the southeast (Florida et el)
I think before we even get to the civil war we would have to speculate on what "north america" would have looked like without the American Revolution.