Statistics for occurrence #1 of “Valley Forge” in entry valley-forge of Harper's Encyclopedia of United States History:

...ene of camp-life at Valley Forge. Above these the original colonial flag with thirteen stars has been carved in the shaft. The inscription reads: To the Soldiers of Washington's Army who Sleep in Valley Forge , 1777-78.
...
Max. Freq. Min. Freq.
Entity Corpus Doc Corpus Doc  
† Valley Forge (Pennsylvania, United States) 154 80 0 0 0 user votes
Valley Forge (Tennessee, United States) 20 0 0 0 0 user votes
Valley Forge (Georgia, United States) 10 0 0 0 0 user votes
Valley Forge (Missouri, United States) 10 6 0 0 0 user votes
Valley Forge (Alabama, United States) 8 0 0 0 0 user votes
† Valley Forge (Pennsylvania, United States) 1 0 1 0 0 user votes

† This entity has been selected by the automated classifier as the most likely match in this context. It may or may not be the correct match.