Selecting a specific topic helps you eliminate hundreds of potential results that would come back in a more broad search. For example, if you search for books based on this string of words - American history until 1865 - the results will give you way too many options, and a majority of them won't meet Dr. Fox's criteria. If you aren't sure what topic you want to research, browse the tabs for inspiration.
Check out these two quick videos that show the difference in search results when you narrow something down!
Some topics covered during this era (approx. pre-1492 - 1630):
Some topics covered during this era (approx. 1630-1763)