Ordered to defensive duties near Washington, D.C. in early October, the Mitchell brothers and their fellow 105th Pennsylvanians were transported south by railroad, and pitched their tents at Camp Kalorama on the Kalorama Heights outside of Georgetown, District of Columbia, before relocating again to Alexandria, Virginia, where they were assigned to the brigade led by Brigadier-General Charles Davis Jameson in the U.S. Army division commanded by Brigadier-General Samuel P. Heintzelman. On November 8, James Mitchell's brother, Alex, was promoted to the rank of first sergeant. Reassigned to duties at Fortress Monroe on March 17, 1862, they then engaged in their first significant combat during the Siege of Yorktown (April 5–May 4) and Peninsula Campaign (March–July 1862), including the battles of Williamsburg (May 5) and &lt;a href="Battle%20of%20Fair%20Oaks"&gt;Fair Oaks/Seven Pines&lt;/a&gt; (May 31), during which James Mitchell's older brother, Alex, was wounded in action. In his battle report, Jameson described how the day's events unfolded: