133rd Engineer Battalion

11 Ordnance Road Brunswick, Maine 04011

Photo of MEARNG Soldiers and Equipment

133rd Engineer Battalion Unit Crest.



Unit Location


Contact Information
Phone 207-430-5466
Mailing Address 11 Ordnance Road Brunswick, Maine 04011

History of the 133rd Engineer Battalion

Although the official date for the beginning of the battalion is 1803, men from Maine had been defending their homes for the past 150 years.  Able bodied men were required to respond to emergencies with their weapon and were formed into militia companies all over the state, which was a part of Massachusetts from 1692 until 1820.  Soldiers from all over the state had fought for Massachusetts in the periodic wars against the Indians and the French.  In 1775, militia companies from York and Cumberland counties marched to Boston to take part in the Battle of Bunker Hill and the siege of Boston which followed.  Militia companies were also active in preventing the British from seizing all of the state during the American Revolution.  

The oldest unit in the state is the 133 EN BN.  It traces its beginnings back to the formation of the Portland Light Infantry in 1803.  The Portland Light Infantry manned the defenses around Portland, such as Forts Preble and Scammell, to prevent British attack in 1814 during the War of 1812.  Other militia units flooded Portland that year, responding to a British invasion from the north that had already seized Bangor and Castine.  Veterans of the Napoleonic Wars, the British were tough and determined fighters.  The British government had decided to take control of Maine and turn it into a colony called “New Ireland.”  Several thousand British soldiers assembled in Castine with seven ships of the line, intent on taking Portland in 1814.  However, militia units from all over Maine put up such a strong defense that after a few skirmishes on the outskirts of town, the British decided that an attack would be too costly and cancelled the invasion. 

Maine men would be called on again in 1861 when war divided the nation into North and South.  The Portland Light Infantry was designated A Company of the 1st Volunteer Infantry and marched off to Virginia.  The 1st Maine Volunteer Infantry reenlisted as the 10th Maine Infantry in 1862, fighting in the battles of 2nd Bull Run and Antietam that year.  When their enlistments expired in 1863, the majority of the regiment reenlisted as the 29th  Maine Volunteer Infantry, and was transferred to the southern theater, fighting in Louisiana in 1863 in the Red River Campaign, and then in Virginia in 1864. 

The 2nd Maine Volunteer Infantry was called into service the same time as the 1st, and saw action during the Seven Day’s Battles, 2nd Bull Run, Antietam, Fredericksburg, and Chancellorsville.  The regiment’s enlistments ran up in 1863, but about half the unit had signed papers to serve for the three years, so they were amalgamated into the 20th Maine Volunteer Infantry.

Also in 1862, the 20th Maine Volunteer Regiment was raised from the Brewer area.  The 20th would be one of the most famous units in the Civil War.  The regiment saw limited action at Antietam but made up for it at the Battle of Fredericksburg, where they were part of the assault element that aimed to take the Confederate defenses on the high ground.  The 20th sustained heavy casualties and was pinned down for over twenty-four hours under enemy fire in the cold December weather.  They were positioned on the far left of the Union line at the Battle of Gettysburg in 1863 and sustained multiple enemy attacks, until the regiment had nearly run out of ammunition.  They had been ordered to hold to the last man.  The regimental commander, COL Joshua L. Chamberlain then gave the order, “Bayonet, Forward!” knowing that he could not withdraw or the enemy would outflank the Union army.  The bayonet charge by the Mainers took the Confederates by surprise and ended their attacks entirely.  For his actions, COL Chamberlain was awarded the Medal of Honor.  The 20th would serve until the end of the war, fighting with distinction in the savage battles through Virginia, such as the Wilderness, Spotsylvania, and Petersburg.

At the end of the war, the Soldiers came home and returned to their civilian lives.  Many kept up their military experience by membership in the 1st Maine Volunteer Militia, organized in 1873.  The 1st M.V.M. had companies in Portland, Augusta, Skowhegan, Auburn, Norway, Bangor, Belfast, Hampden, and Old Town, laying out the footprint for the future Maine Guard.  In 1893, the unit was assigned to the National Guard, and designated the 1st Maine Infantry.  The regiment was mustered into federal service in 1898 for the Spanish American War, but it was plagued by so much disease at its training site in Georgia that the unit was sent home to recuperate and never saw combat.

The 2nd Maine Infantry was also brought under the National Guard in 1893.  It was called into service in 1916 for service on the Texas border and then again in 1917 for World War I.  The 2nd Maine was combined with a unit from New Hampshire to become the 103rd U.S. Infantry.  They served on the front lines in France, taking part in the battles of Champagne-Marne, Aisne-Marne, St. Mihel, Meuse-Argonne, Ile de France, and Lorraine.  The regiment fought well, never giving any ground, and had an excellent reputation.  One Soldier, PFC George Dilboy, was posthumously awarded the Medal of Honor for his actions.

In 1909, the 1st M.V.M. became the 1st Coastal Artillery, with batteries from Bath to Kittery.  In 1917, elements of the 240th were mobilized to protect the Maine coast.  Additional units were mobilized and attached to the 54th Artillery and deployed to France, where they fought on the Marne.   

In the interwar period, the 103rd INF and the 240th CA continued to train and develop as their own entities.  When war came in 1941, they were prepared for service.  The 240th CA manned the defenses on the coast of Maine, preventing any enemy incursion.  The 103rd INF served in the Pacific theater, fighting in the savage battles of Guadalcanal, North Solomons, New Guinea, and Luzon, helping GEN Macarthur liberate the Philippines.   

By the 1950s, the 103rd transitioned to armor, becoming the 103d Armored Cavalry Regiment.  In 1961 it was designated the 20th Armored Regiment.  The 240th served until the 1960s, before being disbanded. 

The 20th AR was designated the 133 EN BN on 23 NOV 1970.  The 133 deployed to Iraq in 2004-2005 in support of Operation Iraqi Freedom II.   

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