Impressed Labor for the Army. To fill the labor requirements caused by the Civil War, the Union army impressed Kentucky slaves to work on various construction projects. Of special concern were transportation and communication initiatives involving roads and railroads. Loyal owners were paid for their slaves’ work, but many grew annoyed at the loss of power and the army’s demands. Over. (Reverse) Enslaved Men to Soldiers- When Camp Nelson was established in 1863, impressed slaves from local farms provided much of the labor to construct the earthen fortifications & improve the roads that brought men & materials to this supply base. The following year, when blacks were finally allowed to enlist, many of the former laborers became soldiers who trained at Camp Nelson. Over.