Dee ihe na-aga n'ihu maka paragraf a - Akụkụ nke Sickles' Excelsior Brigade, ndị 72nd New York sonyere n'ọtụtụ agha ndị kachasị mkpa nke agha ahụ. A kpọgara Washington, D.C., ndị otu nke ndị agha a na mbụ jikọtara na Ngalaba nke Potomac (Sickles 'Brigade), ma kenye ha ịgbachitere obodo ahụ tupu ha sonye na njem ndị agha nke Union na ala Maryland (September 15  October 2, 1861). Mgbe ahụ, e kenyere ha dịka Sickles' Brigade na US Army nke Potomac na Ọktọba dịka akụkụ nke nkewa nke Brigadier-General Joseph Hooker nyere iwu. Ntinye ha ọzọ dị mkpa bịara dịka akụkụ nke ndị agha nke atọ nke United States, Ngalaba nke Abụọ mgbe ha tinyere aka na ọganihu ndị agha Union na Manassas, Virginia (March 10, 1862), njem ahụ sitere na Dumfries ruo Fredericksburg, ijide ụlọ ahịa (March 18), na nyocha site na Liverpool Point ruo Stafford Court House na ọrụ ndị ọzọ na-esote ebe ahụ (Eprel 4). E kenyere ha ọzọ na Mgbasa Ozi Peninsula, ha sonyere na Siege nke Yorktown, Virginia (Eprel 5-May 4, 1862), ma nwee nnukwu ọnwụ na Agha nke Williamsburg (May 5). Ka ọ na-erule oge agha ahụ biri, ihe fọrọ nke nta ka ọ bụrụ ndị otu narị abụọ nke ndị agha ahụ nwụrụ ma ọ bụ merụọ ahụ, ọnụọgụ ọnwụ nke ndị agha ahụ agaghị enwe ọzọ maka oge fọdụrụ n'agha ahụ. N'esote ha lụrụ ọgụ na &lt;a href="Battle%20of%20Seven%20Pines"&gt;Battle of Seven Pines/Fair Oaks&lt;/a&gt; (May 31 <unk> June 1), ndị agha ahụ lụrụ ọgụ na ụbọchị asaa na Oak Grove (June 25), Peach Orchard na Savage's Station
(June 29), White Oak Swamp na Glendale (June 30), na Malvern Hill (July 1 na August 5). Ebufere ya na Peninsula n'oge mgbụsị akwụkwọ nke 1862, ndị agha ahụ hụrụ nnukwu ọrụ na Union's Manassas Station Operations (August 25-27) na Agha nke Abụọ nke Bull Run (August 28-30).