This may sound assumptive, but I have A gut feeling this is an exaggeration by a paper trying to promote the idea of black soldiers, by using the opposition as an example. If it's written in Pennsylvania in 1863, how were they able to verify the confederate use of blacks as combat troops?I have not seen that either, but there is a mention of one in nearby Mobile in this 1863 article:
Sunbury American. (Sunbury, Pa.) 1848-1879, September 12, 1863 - "...That the Confederates armed negroes at the outset of their rebellion we have already shown. They did so in Mobile, even before the battle of Bull Run. They did so in Louisiana before one negro had been allowed to put on the uniform of the United States, and black regiments had an honorable position in their grand parade in the Autumn of '61. They did so in Tennessee, even before they had openly seceded from the Union..."