I had a thread which mentioned this idea.
I'm editing it...
Civil War in 1810s and 1820s results in breakup of US. The European wars during the same period get even worse, leading to revolutions in Europe which weaken the papacy. The Baha'i faith emerges in the mid-1800s in the Mideast.
The Chinese dynasty falls in 1832. During the ensuing civil war, Baha'i spreads through Asia.
The Ottoman empire collapses during the Crimean War. A large group of Baha'i flee to New Orleans to preach, and their faith spreads through N. America.
In 1880, in New Orleans, a popular local politician becomes a Baha'i and begins unifying the continent with a series of alliances, and forms a new nation called the North American Union. He becomes its first and most popular leader.
Technology is more advanced, and capitalism is popular. ATL 1895-1905 is very much like OTL 1920s. A massive economic boom is followed by a stock market crash and worldwide economic depression in 1902, and fascism arises.
The African colonies are neglected and break up in internal strife. The First World War breaks out in 1907 when the czar of Russia is assassinated and Poland asserts its independence.
Britain, Germany, Bulgaria and Poland fight France, Austria, Hungary and Italy over adjoining territories. But Austria, Germany, Hungary and Poland are also fighting over Russian territories. So Poland has allies on both sides of the war, as do some of the lesser states.
The smallpox pandemic of 1911 proves devastating to Europe. The war ends in 1911 in a stalemate.
The leaders of the North American Union had been smart enough to stay out of the war, the pandemic had not struck North or South America, and the North American Union is now the world's only superpower. Baha'i missionaries and doctors begin going to Europe, Asia and Africa...
How's that?