General survey books include Newman's classic reviews have been enjoyed. My undergrad texts were History of Mathematics, by Howard Eves (for those that like working ancient problems in the ancient manner).
The history of science community offers special case math history studies. Calculus, Peter's major interest dates to "Archimedes" E.J. Dijsterhuis, 1987] implied an algorithm stated an approach that found the areas and volumes of a conic section defined by first considering:
4A/3 = A + A/4 + A/16 + A/64 + ...
the 1/4 geometric series approach is connected to Eudoxus
Archimedes reported a finite solution as all calculus methods exactly find the area under curves. In Archimedes' case
4A/3 = A + A/4 + A/12
don't know if a Q.E.D. was attached at this point, Byzantine vellum texts are hard to translate.
The history of number theory was also studied as an undergrad.:
1. History of Number Theory " Oystein Ore. Academia press offers paper back editions.
2. "Elementary Theory of Equations", Samuel Borofsky, 1963 introduced number theory notation to prove classes of theoretical equations.