 officers on the Italian front backed by a powerful concentration of big guns prepare to lay down the opening barrage in the first phase of the campaign that is cracking Nazi lines in this theater of war. Long-toms and Howitz is on target and the enemy is subjected to a pattern of firepower that is devastating. Prick and Sicilian campaigns are eager to learn English for now they are a part of the United States Engineers Corps. Volunteering for non-combat duty they pledged to work against the common enemy Germany commanded by their own officers they will release some 50,000 American regulars for service at the front. Here they learn to be construction engineers to drill and build and blast new roads. Dressed in regulation U.S. Army uniforms they wear green brassards and cap patches bearing the word Italy. Welcome volunteers now working in the cause of the United Nations. Others in Central Park to celebrate I am an American Day. The demonstration is part of nationwide ceremonies held each year to welcome new citizens of the United States. Native Indians the first Americans are among those who stand beneath the banners of the United Nations. Wounded service men are guests of honor as New York's Mayor LaGuardia pays tribute to their heroism. Nations newest Americans pledge allegiance to the country of their adoption. Allegiance to the flag of the United States of America to the Republic for which it stands. One nation indivisible with liberty. Glider assembly field in England have found a practical use for the crates in which their war planes are shipped. Constructing an entire camp from scrap material they've built quite a model city hauled from his packing case and the army boys move in. Cots and all. Mines to remind them of home and very comfortable quarters they are too. Amateurs build their own radio sets. Specially constructed blinds add the homey touch. The barbershop with special rates for enlisted men. You can't beat the army man for ingenuity. Their force demonstrate the terrific destructive power of their latest bombs. 100 pounders in a concentrated salvo. Antipersonnel bombs designed to burst in the air and scatter their fragments among the enemy below. Diving to drop auxiliary gasoline tanks now used as incendiaries. New explosive phosphorus shells. Taking a tank with equipment more powerful than anything yet devised. Newest weapons of the army's ground and air forces now in action against the enemy. Inspects a US 9th Air Force base in Britain. This is one of many Eisenhower tours of his command. Checking every branch of the allied services. Seeing for himself that everything is ready for the approaching day. Here general Eisenhower visits with B-26 Marauder crewmen who are smashing daily at enemy airfields, rail yards and other transport centers. Disrupting German defense plans. Who takes the cockpit of a fighter and tries its gun. Those control tower the Supreme Commander sees Marauders take off on one of an unremitting series of combat missions. In precise formation the Marauders sail high above Europe. Learing the target they dodge anti-aircraft fire. These are official Air Force pictures. Marshaling yard critically important to defense plans are blasted. Their job is crucial in the pre-invasion air campaign. At dusk flares light the runway as they land. And after dark the RAF takes up the job. Four-engined Lancasters roar off with heavy loads. Over a Nazi ammunition dump and stores depot in occupied France the Lancasters unload. They help carry the great and crushing Allied air offensive almost completely around the clock. Day after day, night after night, Allied airmen are smashing up the Nazis on all fronts.