166th Infantry
(Fourth Ohio)
Organized from Companies in South-Central Ohio as the 2d Regiment, Ohio Volunteer Infantry and mustered into Federal service 23 June 1846 at Camp Washington, Ohio; mustered out of Federal service 23 June 1847 at New Orleans, Louisiana
Recognized and mustered into Federal service 1 September 1847 at Camp Wool, Ohio; mustered out of Federal service 26 July 1848 at Cincinnati
Reorganized 1855-1861 as independent companies in Ohio
Consolidated in April 1861 and reorganized at Camp Jackson, Ohio as the 3d and 4th Regiments, Ohio Volunteer Infantry
Mustered into Federal service 27 April and 2 May 1861, respectively, for three months; reorganized and mustered into Federal service 12 June and 05 June 1861, respectively at Camp Dennison, Ohio
3d Regiment mustered out of Federal service 23 June 1864 at Cincinnati; 4th Regiment reorganized in September 1864 as the 4th Battalion, Ohio Volunteer Infantry; mustered out of Federal service 12 July 1865 at Jeffersonville, Indiana
Reorganized 1870-1877 as independent companies in southern and south-central Ohio
Companies consolidated in 1877 and reorganized in the Ohio National Guard as the 5th, 6th and 14th Infantry Regiments
5th and 6th Infantry Regiments consolidated 13 June 1878 and consolidated unit designated as the 6th Infantry Regiment
6th and 14th Infantry regiments consolidated in 1890; consolidated unit concurrently designated as the 14th Infantry Regiment
Reorganized and re-designated 25 April 1898 as the 4th Ohio Volunteer Infantry
Mustered into Federal service 9 May 1898 at Camp Bushnell, Ohio; mustered out of Federal service 20 January 1899 at Columbus
Disbanded 14 April 1899
Reorganized 14 July 1899 in the Ohio National Guard as the 4th Infantry Regiment
Mustered into Federal service 11 July 1916 at Camp Willis, Ohio; mustered out of Federal service 3 March 1917 at Fort Wayne, Michigan
Drafted into Federal service 5 August 1917
Reorganized and re-designated 20 August 1917 as the 166th Infantry and assigned to the 42d Division
Demobilized 17 May 1919 at Camp Sherman, Ohio
Elements of the former 4th Infantry Regiments consolidated with elements of the former 7th Infantry Regiment (see ANNEX 1) and reorganized 21 May 1920 in the Ohio National Guard as the 4th Infantry, with Headquarters federally recognized at Columbus
Re-designated 1 July 1921 as the 166th Infantry and assigned to the 37th Division
Inducted into Federal service 15 October 1940 at home stations
Relieved 16 January 1942 from assignment to the 37th Division
Regiment (less 2d and 3d Battalions) inactivated 01 February 1944 at Fort Sill, Oklahoma (2d Battalion inactivated 22 February 1944 at Camp Hood, Texas; 3d Battalion inactivated 12 February 1944 at Fort Sill, Oklahoma)
166th Infantry reorganized and federally recognized 11 November 1946 with Headquarters at Columbus
Reorganized 1 September 1959 as a parent Regiment under the Combat Arms Regimental System, to consist of the 1st Battle Group, an element of the 37th Infantry Division
Reorganized 1 April 1963 to consist of the 1st Battalion, an element of the 37th Infantry Division
Reorganized 15 February 1968 to consist of the 1st Battalion, an element of the 38th Infantry Division
Reorganized 1 March 1977 to consist of the 1st Battalion of the 73d Infantry Brigade
Withdrawn 1 May 1989 from the Combat Arms Regimental System and reorganized under the United States Army Regimental System
Consolidated 1 September 1992 with the 148th Infantry; consolidated unit concurrently re-designated as the 148th Infantry to consist of the 1st Battalion, an element of the 73d Infantry Brigade (Later re-designated as the 37th Infantry Brigade)
ANNEX 1
Organized 25 October 1877 in the Ohio National Guard from independent companies in Southern and Southeastern Ohio as the 17th Infantry Regiment with Headquarters at Zanesville
Mustered into Federal service 13-30 May 1898 at Camp Bushnell, Ohio, as the 7th Ohio Volunteer Infantry; mustered out of Federal service 6 November 1898 at Columbus
Reorganized 6 November 1899 as the 7th Separate Battalion with Headquarters in Ironton
Expanded and re-designated in 1902 as the 7th Infantry Regiment
Drafted into Federal Service 05 August 1917
Regiment broken up 15 September 1917 with its elements re-designated as units in the 37th Division; 37th Division demobilized 23 June 1919 at Camp Sherman, Ohio
CAMPAIGN PARTICIPATION CREDIT
Mexican War
Buena Vista
Civil War
Antietam
Fredericksburg
Murfreesborough
Chancellorsville
Gettysburg
Wilderness
Spotsylvania
Cold Harbor
Petersburg
War With Spain
Puerto Rico
World War I
Champagne-Marne
Aisne-Marne
St. Mihiel
Meusse-Argonne
Lorraine 1918
Champaigne 1918
DECORATIONS
None