We talked extensively about historical terms for periods of time in the US in a history class I took. I was told by my professor that generically antebellum refers to all time in the US before the civil war (and how I tend to use it), however, the definition as historians use it in their work does not tend to use it that way. Basically, from recollection, this is how she broke it down:

Colonial period - time from colonization until about 5-10 years before the revolutionary war
Revolutionary period - time from about 5-10 years prior to the revolutionary war until about 1783 (I think that was the year she said)
Young Republic period - 1783-about 1820
Antebellum period - about 1820-1860
Bellum period (the war) - 1861-1865
Post Bellum / Reconstruction era - 1865-1877 (some use reconstruction until 1900)

Somtimes periods have more than 1 at a time, such as the industrial age, which covered multiple periods. Different historians use different names as well and a lot of people can't agree on exact years for different periods, so these are just the generally accepted times basically.

Hope this helps.