I've had a look at /r/AskHistorians recommended reading list and used the search bar but I've mainly been finding more social or political histories. I was wondering if anyone could recommend any books which focus on the economic.
Thanks in advance!
What kind of scope are you looking for?
One that my advising professor has been touting for a while is Alfred Chandler's The Visible Hand: The Managerial Revolution in American Business. I'll be reading it this week but haven't yet.
Otherwise a lot of the literature I'm already familiar with from this era combines economic development with other cultural and imperial developments, and rightly so. A couple down that road which you might get a kick out of are:
Hoganson, Kristin. Consumer Imperium: the Global Production of American Domesticity 1865-1920
Jacobsen, Matthew Frye. Barbarian Virtues: The United States Encounters Foreign Peoples at Home and Abroad, 1876-1917
Chang, Kornel. Pacific Connections: The Making of the U.S.-Canadian
If you are interested in how economic development in the U.S. influenced foreign policy, LaFeber's The New Empire: An Interpretation of American Expansion, 1860-1898 is still useful.