Wilentz' historical scholarship has focused on the importance of class and race in the early national period, especially in New York City. Wilentz has also co-authored books on nineteenth-century religion and working-class life. His highly detailed "The Rise of American Democracy: Jefferson to Lincoln" (W.W. Norton, 2005) won the Bancroft Prize. His goal was to revive the reputation of Andrew Jackson and Jacksonian democracy, which was under attack from the left because of Jackson's support for slavery and pursuit of escaped slaves, and especially his harshness toward Indians, including his forced removals of Indian populations from land confiscated by European-ancestry populations. Wilentz returned to the pro-Jackson themes of Arthur Schlesinger Jr., who in 1946 had hailed the pro-labor policies of Northern, urban Jacksonians. He has more recently turned his scholarship to modern U.S. history, notably in "The Age of Reagan: A History, 1974–2008", published in May 2008.