Why is it useful for historians to base certain studies on the analysis of geographic regions

Explanation:

Remember that historians seek for generalisations, as scientist. If they don'r achieve that, so history would not be considered as science.

In order to systematise information (as in every science), they need to segment information by periods of time and study different locations, this way they are able to look for patterns, and there would be focus their special attention, because those patterns are usually specific phenomenons.

the answer to number 5 is fort sumter

one of the main reasons was definitely slavery. back in 1861, republican abraham lincoln was elected and ended up being a major influence in the slavery business. slavery greatly affected the texas economy because back in 1845 during the annexation of texas, slaves became a big part of the texas population. many texans that were in favor of the secession influenced groups through party ties.