The 2nd New York Volunteer Infantry Regiment was an infantry regiment that served in the Union Army during the American Civil War.
 It is also known as the Troy Regiment.
The 503rd Infantry Regiment, formerly the 503rd Parachute Infantry Regiment (PIR) and the 503rd Airborne Infantry Regiment (AIR), is an airborne infantry regiment of the United States Army.
 The regiment served as an independent regiment in the Pacific War during World War II; at Fort Campbell, Kentucky; in Okinawa, Japan; and in Germany.
 Regimental elements have been assigned to the 2nd Infantry Division, the 11th Airborne Division, the 24th Infantry Division, the 82nd Airborne Division, and the 173rd Airborne Brigade Combat Team.
 Regimental elements have participated in campaigns in the Vietnam War, Operation Enduring Freedom–Afghanistan, and Operation Iraqi Freedom.
 The regiment claims 15 Medal of Honor recipients: two from World War II, 10 from Vietnam, and three from Afghanistan.
 A parent regiment under the U.S. Army Regimental System.
 The regiment's 1st and 2nd Battalions are active, assigned to the 173rd Airborne Brigade, based at Caserma Ederle, Vicenza, Italy.
The 299th Cavalry Regiment, formerly the 299th Infantry Regiment, nicknamed the "The Koa Regiment", is a unit of the Hawaii Army National Guard.
 It was established in 1923 from the old 2nd Hawaiian Infantry Regiment, and it served during World War II as part of the 24th Infantry Division.
 The name "Koa" comes from the Hawaiian word for "Warrior", and is currently headquartered in Hilo, Hawaii.
 The 1st and 2nd Battalions, 299th Infantry were federally activated in 1968 to support the United States Army Pacific during the Vietnam War.
 More recently 2nd Battalion, 299th Infantry Regiment deployed to Iraq and again after being re-flagged in 2007 as 1st Squadron, 299th Cavalry Regiment.
The 19th (Dockery's) Arkansas Infantry (1862–1865) was a Confederate Army infantry regiment during the American Civil War.
 There were two other Arkansas units which were designated as the 19th Arkansas.
 Dawson's 19th Arkansas Infantry was organized at Nashville, Arkansas, on November 21, 1861.
 Hardy's Arkansas Infantry Regiment, which is also occasionally referred to as the 19th Arkansas was organized in 1863 from those parts of Dawson's 19th Infantry Regiment, the 24th Arkansas Infantry Regiment and Crawford's Arkansas Infantry Battalion, which escaped capture at the Battle of Arkansas Post.
The 1st Florida Infantry Regiment was an infantry regiment raised by the Confederate state of Florida during the American Civil War.
 Raised for 12 months of service its remaining veterans served in the 1st (McDonell's) Battalion, Florida Infantry from April 1862 on.
 In August the depleted battalion was consolidated with the 3rd (Miller's) Battalion into the reorganized 1st Florida Infantry Regiment again.
 In December 1862 it merged with the 3rd Florida Infantry Regiment and received the form it kept till the war's end as the 1st and 3rd Consolidated Florida Infantry Regiment.
 Fighting as part of the Army of Tennessee in the Western Theater of the American Civil War it was surrendered on April 26, 1865.
Since the establishment of the United States Army in 1775, three regiments have held the designation 28th Infantry Regiment.
 The first was a provisional unit that was constituted on 29 January 1813 and served during The War of 1812.
 The second was a reorganization and redesignation of 2nd Battalion, 19th Infantry Regiment on 1 October 1866 for the American Indian Wars.
 This incarnation of the 28th Infantry Regiment lasted until 15 March 1869, when it was consolidated back into the 19th Infantry Regiment.
 The third version of the 28th Infantry Regiment is the one that has the permanent designation and history, and is the one this article is about.
The 105th Infantry Regiment was an infantry regiment of the New York Army National Guard that saw combat in the American Civil War, World War I, and World War II.
 Originally, it was known as the 2nd New York Volunteer Infantry Regiment, but it was redesignated in 1916.
 The 105th fought as a part of the 27th Infantry Division during both World Wars, and was highly decorated for its actions during the Battle of Saipan, where its dogged defense against the largest Japanese Banzai charge of the war decimated its ranks, but prevented the American effort on the island from collapsing.
The 115th Infantry Regiment, Maryland Army National Guard was an infantry regiment of the United States Army.
 It traced its roots back to the American Revolutionary War, although its official U.S. Army lineage begins in 1881.
 The units to which the 115th Regiment claims lineage served in the Revolutionary War and the Civil War, but the 115th itself was only credited with service in World War I, World War II, and the Global War on Terror.
 Prior to the reorganization into the 58th Brigade Combat Team, the 1–115th was part of the Third Brigade, 29th Infantry Division (Light).
 In 2006, the 115th was consolidated (merged) with the 175th Infantry Regiment.
 As a result of this consolidation, it no longer exists as a separate regiment.
The 18th Arkansas Infantry (Marmaduke's) (1861–1865) was a Confederate Army infantry regiment during the American Civil War.
 The unit was also briefly identified as the 1st Arkansas Infantry Battalion.
 The unit was most often referred to as the 3rd Confederate Infantry Regiment.
 The designation "Confederate Infantry Regiment" was intended to convey the difference between Provisional Confederate Army units and Regular Confederate Army Units, with Provisional units being those regiments who received a state designation such as "XX Arkansas Infantry Regiment".
 In practice, the designation was most often utilized when Regiments were assembled utilizing companies from more than one confederate state.
 The "3rd Confederate Infantry Regiment" is occasionally misidentified as the 3rd Arkansas Infantry Regiment commanded by Colonel Van H. Manning.
The 39th Arkansas Infantry Regiment or Cocke's Arkansas Infantry Regiment (also known as "Johnson's regiment," "Hawthorn's regiment," "Cocke's regiment," and "Polk's regiment") was an infantry formation in the Confederate States Army during the Civil War, and was successively commanded by Colonels A. W. Johnson, A. T. Hawthorn, J. B. Cocke, and Lieutenant-Colonel C. Polk.
 It was mustered into service on June 17, 1862, at Trenton, Arkansas, remaining active through May 26, 1865.
 When Major-General Sterling Price's staff decided to designate all infantry regiments in the District of Arkansas as "Trans-Mississippi rifle regiments", the 39th Arkansas Infantry Regiment was designated as the 6th Trans-Mississippi Rifle Regiment.
 One other Arkansas regiment was designated as the 39th Arkansas Infantry; that regiment being successively commanded by Colonels Hart, McNeill, and Rogan.
 It was originally designated as the 39th Arkansas, but later redesignated as the 30th Arkansas Infantry Regiment.
 The 39th served in the Trans-Mississippi Theater of the American Civil War and participated in all of the principal engagements in that department before disbanding on May 26, 1865.

Question: What is the infantry regiment that served in the Union Army during the American Civil War, that was also known as the 105th Infantry Regiment?
Answer: 2nd New York Volunteer Infantry Regiment