The 665th Engineer Topographic Battalion (December 17, 1943 - December 1946) was part of the U.S. Army during World War II and provided technical support in the form of surveying, drafting, and map production. Activated on December 17, 1943, at Fort McCoy, Wisconsin, the battalion initially consisted of twenty-eight men and an officer from the 650th Engineer Topographical Battalion, and five other officers from other units. Members of the unit had participated in the Army Specialized Training Program and had experience in topographical survey and mapping processes along with photomapping and reproduction techniques. The battalion was also supplemented with personnel who had received the necessary training as civilians. The unit spent the almost all of 1944 training in the United States, which included marksmanship drills, chemical warfare, and demolition instruction, along with winter training exercises in Wisconsin testing the army's newest winter clothing. The battalion embarked for Europe in New York City on December 8, 1944, and arrived two weeks later in Avonmouth, England. It left for the Theater of Operations from Southampton on January 30, 1945, and deployed to Belgium where it set up operations in Altembrouck, Belgium, and Castle Mheer in Mheer, Holland. Once their equipment was ready, the battalion began creating topography mapos from aerial photographs and ground survey information for the Ninth Army. It produced over 3,000,000 impressions in the first month. They moved to Hoensbroek, Holland, with map storage and distribution staying in Maastricht, Holland. Two weeks later the battalion moved to Mönchengladbach, Germany. The unit moved several more times in March and April 1945 to remain near the Ninth Army headquarters. After the war in Europe ended, the 665th continued making maps and conducting surveys for the Occupation forces. By mid-June the battalion had moved back to France in preparation for redeployment to the Pacific. However, the war in the Pacific ended before they left France. Some of the men in the unit (those with enough points) were discharged starting in October while the rest were transitioned to Occupation duty. The unit was deactivated in December 1946.