We'll say that
https://en.wikipedia.org/wiki/Venezuelan_crisis_of_1902–1903 this turns Venezuela into a german protectorate, and results in the US being more directly hostile to Germany; idk, maybe McKinley doesn't die and TR isn't in charge to bully the germans off at that point. regardless, this would be pretty implausible, but it works. Maybe as a result of this, the US guarantees Belgium or China, basically out of spite. for the sake of this, we'll go with Belgium. now, this would change the calculus of the invasion, but eh.
- the USN clowns on whatever Germany has in the Caribbean, and installs a friendly government in Venezuela, analogous to the OTL mandates. whatever, it was just to ruin german-american relations enough
- While America would declare war in 1914, it would take until 15 to get troops directly there. maybe 16, depending on SA. we'll say that the USN in the Caribbean means less shipping so the western front goes slightly better for Germany, which means when the doughboys arrive they can't just roll over em with numbers combined with Russia
- as a side note, we'll have Russia do even worse somehow and send them packing in 1916. Reds win so i don't have to consider them too much.
- America is doing the trench warfare and all that stuff alongside the rest of them. They'd probably be deployed all over the west, but we'll say mostly in Belgium and italy, since those would be the fronts most in need of shoring up.
- The Germans take Paris by 1918 after the collapse of russia, overwhelming the americans
now, OTL, WW1 was pretty good for women, since it made prohibition a more 'patriotic' position due to rationing and because of anti-german stereotypes, which also allowed women to push for the vote more effectively. that would go over more or less OTL, actually. The german-americans would be more actively assimilated throughout the war, since OTL they were only really targeted really late.
obviously, we can't know exactly how the 20s would go, but i would assume poorly. France, Britain, and Italy would all default on their debts and the new russian government doesn't acknowledge them. America would be booted out of Europe by this, especially since the germans were not a freely trading people. The 20s wouldn't be roaring; if anything, it'd be a long depression. millions of men are coming home to find their jobs unavailable, and the military economy that fuelled the war would be downsizing rapidly. The dustbowl might actually be worse due to the increased need for rationing. This would likely result in a lot of reformist populism. Not fascism or communism, but people like Debbs, FDR, or Long would become a lot more popular going into 1928, especially if the stock market crashes.
we won't get kaiserreich unless france and britain do actually succumb to some wild revolution and destroy what trade the states does have left, but eh