"This failure is owing to several causes. When first invited to enlist the negroes had hardly learned to realize the promised change in their condition - to comprehend as a possibility that they had been so suddnely lifted out of the utter degradation of chattelism to the dignity of the right of bearing arms. They were far from being sure of their freedom.
Several occurences had led them to doubt our good faith, who had professed to come as their deliverers. They were fully aware of the contempt, oftentimes amounting to hatred, of their ostensible liberators. They felt the bitter derision, even from officers of high rank, with which the idea of their being transformed into available soldiers was met, and they saw it was extended to those who were laboring for their benefit. When their own good conduct had won them a portion of respect, there still remained widespread distrust of the ultimate intentions of the government.
A large number was required as laborers in the various departments of Governmetn service. But one of the chief causes of failure is the fact that a comparative few of the negroes are physically fit for soldiers; many suffer under some visible or concealed infirmity, produced by the rigor, cruelty, and barbarity of their treatment, and the evidences of the most unsanitary conditions of life on the plantations. In these circumstances the recruiting went slowly, when the major general commanding (Genreal Foster) ordered the indiscriminate conscription of every man in the department." And then you continue.
Taken in context, something unknown amongst the southron contingent, it's clear that the blacks in your quote were being conscripted for laborers and not as soldiers. General Saxton's report is very interesting in that it details the abuses that the average white soldier heaped on the local black population. Given that it's really amazing that upwards of 200,000 would volunteer for military service. But serve as volunteers they did, not as conscripts as you would have us believe. And their service in combat units was encouraged by the government and officially recognized. Unlike the blacks in the confederate ranks who were there without government saction and not as combat soldiers. Careers of those who suggested blacks be recruited as combat soldiers, men General Cleburne, were damaged by such suggestions because virtually all the southern leadership believed, as General Lee did, that blacks were best left in slavery and nowhere else. And when the south, with everything crumbling around them, finally broke down and authorized black combat troops they still could not be made to take the next step and offer those slaves who served their freedom. Had they served and had the south won they would have gone from the battlefield to the cotton field. As the southern leadership believed was the right and proper place for them.
To put Saxton's remarks in context, let's look at an excerpt from the Union conscription order he complained about in my quote.
I. All able-bodied colored men between the ages of eighteen and fifty, within the military lines of the Department of the South, who have had an opportunity to enlist voluntarily and refused to do so, shall be drafted into the military service of the United States, to serve as non-commissioned officers and soldiers in the various regiments and batteries now being organized in the department. [Source: Official Records, Volume IV, page 621]
You had asked if some conscripts could be pointed out. I did just that. I have no doubt that the majority of blacks in Northern units were volunteers. Where did I say they were not? I just pointed out some that were conscripted.