The American nation: its executive, legislative, political, financial, judicial and industrial history : embracing sketches of the lives of its chief magistrates, its eminent statesmen, financiers, soldiers and jurists, with monographs on subjects of peculiar historical interest, Volume 2. Williams Publishing Co.
Nevins,  Allan. Ordeal of the Union, vol. 1: Fruits of Manifest Destiny, 1847–1852 (1947), covers politics in depth. Online free to borrow
Quist, John W. "The Election of 1848."in American Presidential Campaigns and Elections (Routledge, 2020) pp. 328–348.
Smith, Elbert B. (1988). The Presidencies of Zachary Taylor and Millard Fillmore. University Press of Kansas. ISBN 978-0-7006-0362-6.
Smith, Elbert B. (2011). President Zachary Taylor : the hero president. New York: Nova Science Pub Inc. ISBN 978-1608769124.

Further reading
General
McKinley, Silas B.; Bent, Silas (1946). Old Rough and Ready: The Life and Times of Zachary Taylor. New York: Vanguard Press.
Graff, Henry F., ed. (2002). The Presidents: A Reference History (3rd ed.).
Silbey, Joel H. (2009). Party Over Section: The Rough and Ready Presidential Election of 1848. Lawrence, Kansas: University Press of Kansas. ISBN 978-0-7006-1640-4. OCLC 263497977.
Silbey, Joel H. (2014). A Companion to the Antebellum Presidents 1837–1861. Chichester, West Sussex, UK: Wiley. ISBN 978-1-118-60929-3. 