Statistics for occurrence #1 of “Tennallytown” in chapter 6, page 94 of The Photographic History of The Civil War: in ten volumes, Thousands of Scenes Photographed 1861-65, with Text by many Special Authorities, Volume 5: Forts and Artillery.:
...h the occasion really demanded.
The securing of the roads was the first consideration.
The main road which followed the general line of the crest between Rock Creek and the Potomac, branched at Tennallytown , about a mile south of the District line, and entering and leaving the town were other important roads.
As this was on fairly high ground it was selected as a proper point for a work, and Fort Penn...
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