1844

[M]

By 1844, we can tackle Britain alone on land, but bring in Mexico and we're in trouble.

A 54'40 scenario without Texas annexation could be interesting... You might get a U.S. grabbing Canada, pro-slavery Scott administration 48-56 presidency annexes Texas (where Houston has returned as president, now governor) and wins a war with Mexico, annexing the whole thing. Houston-Davis administration, Whig party decays but the moderate Houston keeps the country together. After his death in '63, Davis runs for reelection and narrowly beats Seward. Crittenden amendment passes, and Crittenden is Jeff Davis's veep... Mexico unhappy with enforced slavery, and Fremont led a California rebellion which got him disgraced and imprisoned. Anyway, Davis-Crittenden reelectedin '64, buy Alaska (Breckenridge's Icebox?) and Greenland; Central America absorbed. In '68 Thad Stevens (the Republicans got angry and went to radical) and Crittenden are beaten by Zebulon Vance, the last Whig. Cuba purchased, Hispaniola annexed. In '72 Old Abe Lincoln came out of the wilderness, and a Confederacy led by old Judah Benjamin declares war... supported by Disraeli's UK. It's the minimal Confederacy- SC, Georgia, Alabama, Mississippi, Florida, and Louisiana. Union armies- led by W.T.Sherman in the west and Stonewall Jackson in the East- blitz the South. In the ensuing naval war with Britain we start off in trouble, but Farragut's navy regroups and eventually gains local dominance. Caribbean, Bermuda, acquired through purchases and the peace treaty with Britain. Britain acquires the Faeroes and Iceland as a special self-governing dominion to counter the new American threat (Denmark is feeling very pushed around now). Lincoln reelected in '76, thanks partly to Reconstruction, though Lincoln's reconstruction is quite light. In '80 the Union general George Armstrong Custer beats former Confederate Joe Wheeler. The Civil war was quite a bit lighter (smaller Confederacy, much more industrialized North) and reconstruction was less harsh; the country's divisions are much less intense and Manifest Destiny is back with a vengeance. For Custer, there's still a lot of Manifest Destiny to be fulfilled... a whole 'nother America to the south of Panama State.

So, we have
Clay (W) '44-'48
Oregon, Canada acquired

Scott (W) '48-56
Texas, Mexico acquired

Houston (D) '56-'63
Crittenden amendment passed, Central America acquired

Davis (D) '63-'68
Alaska, Greenland acquired

Vance (W) '68-'72
Cuba, Hispaniola acquired

Lincoln (R) '72-80
Civil War; Caribbean, Bermuda acquired

Custer (R) '80-
South America is in trouble