The USA in the 19th Century:
J. M McPherson, Battle Cry of Freedom
D. M Potter with D. Fehrenbacher, The Impending Crisis 1846-61
A. Farmer, Civil War and Westward Expansion 1803,-1890
Tudors:
Ian Mortimer, The Time Traveller’s Guide to Tudor England
T. Penn, Winter King: The Dawn of Tudor England
Russia:
O. Figes, A People's Tragedy: The Russian Revolution
Simon Sebag Montefiore, Saschenka (fiction)
Simon Sebag Montefiore, Young Stalin
Robert Service, Lenin
Don't forget that you also have access to the following two magazines: