His father, Isaac Jackson, despite his religious beliefs, had joined the United States Army during the War of 1812, and died six years later from disease contracted while in the service.

In 1845, he was appointed by President James K. Polk as a lieutenant in the revenue service, and subsequently was sent to Mexico as the bearer of dispatches to General Winfield Scott during the Mexican-American War.

His division commander, fellow Pennsylvanian George G. Meade, later wrote: The Third brigade had not advanced over one hundred yards when the battery on the height on its left was re-manned, and poured a destructive fire into its ranks.

"[2]General Jackson had ridden forward to give the contemplated order; but before he could relay it, he was struck in the head by a Confederate volley that also killed his aide.

[3] In mentioning his death, Meade wrote, "The public service has also to mourn the loss of Brigadier-General C. Faeger [sic] Jackson, an officer of merit and reputation, who owed his position to his gallantry and good conduct in previous actions.