An incorporated village in Marion County, twelve miles west of Palmyra, — which is its shipping and banking point. It was laid out in December, 1835, by William Muldrow. It has two churches, a public school and fourteen business houses, including stores and shops. Population in 1899 (estimated), 240. In 1861 Philadelphia proved to be the only place in the county in any wise equipped for the Civil War. A company of about thirty men was armed with muskets and bayonets. Under Captain Robert E. Dunn they started for Boonville, but when they reached Paris, Missouri, June, 17, 1861, the Boonville engagement was over. The greater part of the company returned home, but Captain Dunn, with a half dozen of his men, kept on to Cowskin Prairie, and at Wilson’s Creek Dunn fought as a private with conspicuous gallantry. One of the six pounders made by Cleaver & Mitchell, at Hannibal, Missouri, had been placed in a wagon bed and hauled to Philadelphia, where the piece was mounted. It did good service in General Green’s command and on the Missouri River. This cannon, with its companion nine-pounder, rounded up the steamer “Sunshine” so as to enable Green’s brigade to cross to the investment of Lexington, Missouri. – Thomas H. Bacon

Source: 1901 Encyclopedia of the History of Missouri