History

Fermat's Little Theorem
Historical comments by John Cosgrave.
http://www.spd.dcu.ie/johnbcos/fermat's_little_theorem.htm

A Guide to the Emil Grosswald Papers
Held at the Archives of American Mathematics, Center for American History, University of Texas at Austin.
http://www.lib.utexas.edu/taro/utcah/00224/cah-00224.html

Historical Essays in Number Theory
MSs by Peter Roquette.
http://www.rzuser.uni-heidelberg.de/~ci3/manu.html

History of Arithmetic and Number Theory
A bibliography by D. Joyce.
http://aleph0.clarku.edu/~djoyce/mathhist/arithmetic.html

Mathematical Manuscripts at Trinity College Cambridge
Includes papers of Davenport, Hardy, Littlewood, Ramanujan.
http://rabbit.trin.cam.ac.uk/~jon/Msscolls/type.html#Maths