There were only seven shows in the can for this season, I believe. The last show of the season was last week. I checked the schedule, and the History Channel is going to start showing reruns next Tuesday (1/13) starting with the coal train episode. I know a lot of people thought the host was over the top, including me, and some nitpicked the show, but overall I found the show to be entertaining and informative. I hope they bring it back with new episodes soon.
Here's a link to the History Channel's schedule page. You can look up shows for up to two weeks in advance.
History Channel schedules