^It depends when when the technology began to differ from the real universe. Did the American Civil War have the biplanes and tanks like we had in the first world war one? The Spanish American War? Whatever the case is, the odds are that the history would be very different up to just before the Great Depression. For all we know, the Great Depression would have never happened. Nazism didn't rise to the power it had. Thus no second world war two.
But on the other hand, we might have had a similar large-scale war earlier, like in the late 19th Century. Also, without World War Two, USSR might not have risen to the heights of power it had in the 50s and 60s. The space age would have been pretty different, since it would have started 50 years earlier (let assume). with the first moon landing in 1919, when JFK was a little tyke thus preventing him from making that famous promise of his.
