On Thursday, October 6, 2022 at 2001 EST, a mysterious portal opens up in the US National Herb Garden in Washington, D.C. It leads to what would have been the neighborhood of Blue Plains if humanity had never existed, along with 46 other portals arrayed in a partial imaginary circle concentric with the square boundaries of the District of Colombia. Further investigation leads to the discovery that this hubworld is not located on a proper planet, but a flat dymaxion projection of the Earth situated in a spherical pocket dimension.
Each of the 47 portals leads to a different point in American history, one for each presidential administration. For example: the 1st portal led to the base of the newly rechristened Capitol Hill two and half months before the laying of the cornerstone of the building that bears its name; the 16th portal led to the Capitol Riverfront neighborhood, just miles away from Confederate territory; the 35th portal led to Anacostia mere weeks before the outbreak of the Cuban Missile Crisis; and so on.
Here are the list of dates corresponding to when each portal is opened in each timeline:
07-09-1793
05-30-1978
01-11-1805
11-22-1813
08-10-1820
10-13-1826
12-30-1833
03-28-1839
03-17-1841
05-12-1843
01-13-1847
02-28-1850
04-19-1852
06-06-1856
08-01-1859
02-11-1862
12-13-1866
01-27-1874
07-09-1879
06-21-1881
11-08-1883
01-25-1887
02-24-1891
04-24-1895
02-28-1899
05-14-1907
10-06-1910
09-27-1916
02-24-1922
07-06-1926
08-05-1930
03-22-1937
11-16-1949
07-31-1956
09-25-1962
10-15-1964
11-16-1972
01-12-1976
07-27-1979
10-21-1983
05-28-1990
09-12-1997
02-09-2004
03-16-2015
04-03-2019
10-06-2022
07-31-2030
Now at the moment, I don't have much in the way of events that happen after the opening of the portals beyond some general ideas, but feel free to suggest anything that might come to mind - although since this is a semi-collaborative TL, I reserve the right to veto any new ideas provided I give a good reason as to why. I also have the precise location for each of the portals listed in private, but since it might not be a good idea to get so specific I'll wait to see what you guys think of putting it out there before I do anything.
Finally, I'm well aware of the sheer madness associated with trying to tell the stories of 47 separate timelines within a single thread, as even a concerted group effort would be quite unable to describe them all in sufficient detail. Therefore, I suggest that a focus be set on at least four Earths in particular: Earth-4, Earth-16, Earth-32, and Earth-46. These represent some of the most eventful or currently relevant periods of US history, and they might be a good starting point to start exploring inter-timeline relationships.
Sorry if I went a bit too formal with my writing, though. I kinda doubt this is going to go anywhere, but there's no harm in trying, I guess.