<h2>Similar events and trend often take place on different places during the same periods.</h2>
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.
His most challenging and unresolved problem was the takeover of the U.S. Embassy in Tehran, Iran in 1978 by Islamic fundamentalists and the taking of more than 40 American hostages. Carter was unable to secure their release during his presidency. The were released once Ronald Reagan took office.
