The 787th Tank Battalion was organized 14 January 1943 in the United States Army, 3d Battalion, 16th Armored Regiment, within the 16th Armored Division.
 Six months later, almost to the day, 16 AR Rgt.
 was activated to train for combat service at Camp Chaffee, Arkansas 15 July 1943.
 On 10 September 1943 the regiment was relieved from division command of the 16 AD.
 The regiment was reorganized to battalion strength and redesignated 787th Tank Battalion.
 Becoming an independent tank battalion they, like most of their brother tank battalions, were assigned to infantry regiments/divisions where they were most needed throughout the war.
 So often was the case that as records show only one tank battalion stayed with the original assigned unit throughout the duration of WWII.
The 824th Tank Destroyer Battalion was a tank destroyer battalion of the United States Army active during the Second World War.
 It saw service during 1944–45 in the European Theater of Operations, primarily attached to the 100th Infantry Division in an infantry support role.
 After fighting through France and southern Germany, the battalion ended the war in Austria.
The 628th Tank Destroyer Battalion was a tank destroyer battalion of the United States Army active during the Second World War.
 It was redesignated the 628th Tank Battalion after the end of the war, and today exists as the 103rd Armor Regiment.
The 705th Tank Destroyer Battalion was a tank destroyer battalion of the United States Army active during the Second World War.
 It was originally formed from artillery elements of the 5th Armored Division, and its lineage is today perpetuated by the 75th Cavalry Regiment.
17th Armored Engineer Battalion are part of the 2nd Armored Division "Hell on Wheels".
 During World War II, they were active in North African Campaign, and Western Europe Campaign.
 17th Armored Engineer Battalion was founded on 1 October 1933 as part of the USS Army.
 First called "17th Engineer Battalion (Heavy Ponton), Motorized".
 It was renamed on 10 July 1940 to 17th Engineer Battalion (Armored) and assigned to the 2d Armored Division.
 The unit became active and started training 15 July 1940 at Fort Benning, Georgia.
 Renamed again on 8 January 1942 as the 17th Armored Engineer Battalion.
 The Battalion is now based at Fort Hood, Texas.
 Battalion motto is "We pave the way".
 Task of the 17 include construction and demolition tasks under combat conditions, like constructing and breaching trenches, tank traps and other fortifications, bunker construction, bridge and road construction.
 Along with building destruction bridges and other physical work in the battlefield are needed.
 They also lay or clear land mines.
 The 17th facilitates the movement and support of friendly forces while slowing the enemy's forces.
The 12th Armored Division was an armored division of the United States Army in World War II.
 It fought in the European Theater of Operations in France, Germany and Austria, between November 1944 and May 1945.
The 818th Tank Destroyer Battalion was a tank destroyer battalion of the United States Army active during World War II.
 It first saw combat in July 1944, when it deployed into the Normandy beachhead in preparation for the breakout into France by Lieutenant General George Patton's Third Army.
 Working closely with the 5th Infantry Division, it moved through northern France up to the Moselle region, where it was involved in the Battle for Metz through September, October and November.
 In December, it disengaged from defensive positions along the German border and was moved north to fight in the Battle of the Bulge with the 26th Infantry Division.
 After securing the Allied flanks and mopping up the Bulge, it refitted for two months before fighting south along the Siegfried Line and crossing the Rhine in March.
 In April and early May, it rushed through southern Germany into Austria and Czechoslovakia, where it ended the war.
 After a brief spell of occupation duties, it was returned to the United States and disbanded in November.
 During the European campaign, the battalion lost a total twenty-six men and eight tank destroyers in combat.
The 827th Tank Destroyer Battalion was a tank destroyer battalion of the United States Army active during the Second World War.
 It was activated in April 1942 as a segregated African American unit, deploying to Europe at the end of 1944 and attached to 12th Armored Division.
 It saw action during Operation Nordwind in January 1945, where elements of the battalion performed creditably.
 However, its overall combat record was marred by severe disciplinary problems and insufficient training.
 It was withdrawn in February, and assigned to rear-area duties; while it nominally remained active for the remainder of the war, it had been effectively disbanded.
The 614th Tank Destroyer Battalion was a tank destroyer battalion of the United States Army active during the Second World War.
 The unit was activated in 1942 and trained through the late summer of 1944.
 Arriving on the Normandy coast in October, they moved to the Metz, France, area, seeing their first action in late November.
 In early December, they were attached to the 103rd Infantry Division, a pairing that was to last through the end of combat in Europe.
 The 3rd Platoon, Company C, of the 614th was the first African-American unit to receive a Distinguished Unit Citation during World War II.
 They received credit for the Northern France, Rhineland, Ardennes-Alsace and Central Europe campaigns.
The 654th Tank Destroyer Battalion codename: Highroad was a tank destroyer battalion of the United States Army active during the Second World War.
 They landed at Omaha Beach on July 11, 1944.
 The Battalion was activated on 15 December 1941 at Fort Benning, Georgia.

Question: When was the segrated 12th Armored division ttached tot the 827th Tank Destroyer Battalion activated?
Answer: April 1942