Artillery of World War I

The artillery of World War I was used to counter the trench warfare that set in shortly after the conflict commenced, and was an important factor in the war, influencing its tactics, operations and incorporated into strategies that were used by the belligerents to break the stalemate at the front. World War I raised artillery to a new level of importance on the battlefield. The years of the First World War had provided several developments in artillery warfare. Artillery could now shoot farther and more explosively than ever before. Because of this, enemies in trenches would no longer always be safe, and would constantly be fired upon. In some areas, artillery concentration would be common, several artillery firing onto an area – such as a line of trenches, each firing several rounds per minute lasting for hours. Artillery barrages would also be used before an infantry battle, to create a distraction away from the place of attack, so that the enemy's numbers would be fewer, or they would fire at the paths going from the area that would be attacked so that the enemy reinforcements would not be able to reach the area without getting hit. Mortars were revived by the Germans because of their ability to shoot at an angle above 45 degrees, and therefore could theoretically (although not often) land directly in an enemy's trench before exploding for maximum damage. Artillery shells were used for gas release by the German troops in 1915, and the Allies followed their example after the First Battle of Ypres where the chlorine gas thrown by the British changed direction and hit their own men.

United States Army artillery
When the United States entered the war in 1917, the condition, the equipment, the training, and the discipline of the American field artillery were nothing short of chaotic.

Unprecedented American production and ample Allied support provided the weapons with which the American artillery had to fight. Materiel used by the Americans was mostly French, and during the war only 100 American weapons saw action. The French alone contributed 3,834 field pieces and mortars, as well as 10 million rounds of ammunition. The old 3-inch gun—the Army possessed only 600 at the beginning of the war was replaced by the French 75-mm gun. The French 75-mm gun was the best of its type. Its recoil system worked on glycerin and air, it was easy to aim, and it could be fired more rapidly that other artillery pieces. It was able to shred infantry columns to pieces but was unable to penetrate reinforced earthworks. Germany had about 3,500 105-mm and 155-mm howitzers; France, about 300.

In late 1917, American troops moved into quiet sectors of the Western Front. The honor of firing the first American artillery round in World War I went to Battery C, 6th FA Battalion (later the 2d Battalion, 6th Artillery, 3d Armored Division), on October 23, 1917. Although the war seemed to have settled down to stabilized trench fighting, General John J. Pershing insisted that American troops be trained in open warfare; in the end, Pershing's instincts had served him well. By the time American troops began to appear on the battlefield in significant numbers, the war had indeed become more mobile, with Ludendorff's last push towards Paris.

In the spring of 1918, American troops were thrown in at Chateau-Thierry to halt General Erich Ludendorff's massive offensive. Counterattacking under a heavy artillery barrage, they cleared the Germans out of Belleau Wood in 2 weeks of hard fighting.

The capture of plans for a reopening of the German attack in the Champagne region on the eve of July 4 enabled Allied artillery to lay down a devastating barrage 1 hour before the enemy's guns were scheduled to commence their preparation for the attack. The 75mm guns of the 42d Division, standing hub to hub, joined the artillery of the Allies in shredding the German assault. The 38th and 3d Divisions stood firm on the Marne despite the ferocity of Germany's last desperate gamble for victory. Finally, the enemy fell back and a massive Allied attack was launched in the direction of Soissons, while the Saint Mihiel salient, which the Germans had held for years, was sealed off by Pershing's First Army.

Again, artillery played a key role. About 3,010 guns of 26 calibers and 46 models poured 74 types of ammunition into the salient in the 4 hours and 45 minutes prior to the attack. Altogether, 838,019 rounds of ammunition—high explosive, smoke, and nonpersistent gas—were expended in a single battle. The careful preparation of the attack and the air superiority that had been achieved paid off in terms of 16,000 German prisoners and 443 artillery weapons captured.

In the final Allied offensive of the war, the First and Second US Armies, operating between the Meuse and the Argonne, were thrown forward against the Hindenburg line. An unprecedented artillery bombardment supported the advancing infantry. French and American artillery averaged one gun per 8 yards of front, whereas the enemy could muster only one gun per 25 yards. In the American sector over a quarter of a million rounds rained down on the enemy in the first day of the attack, alone.

Stunned, but taking a heavy toll of American troops, the enemy pulled back. By the end of October, the last German defensive stronghold, the Kriemhilde Stellung, had been reached. Blasted by the massed firepower of divisional, corps, and army artillery directed by careful aerial observation, the enemy offered little resistance to the infantry attack that followed the 2-hour barrage of October 31, 1918. The Allied forces rushed for Sedan and the German border. On November 11, 1918, the German Government capitulated.

Soon after the armistice of November 1918, the War Department urged Congress to authorize the establishment of a permanent regular army of nearly 600,000 and a 3-month universal training program, which would facilitate a quick expansion of this force to meet the requirements of a new major war. The Congress and the American public rejected these proposals. They believed that the defeat of Germany and the exhaustion of the other European powers guaranteed that there would be no major land war for years to come. The possibility of war with Japan was recognized, but the American powers assumed that such a war would be primarily a naval conflict. Therefore, the fundamental factor in the military policy of the United States during the next two decades was reliance on the US Navy as the first line of national defense.

Usage of artillery
The artillery Arm developed several new methods and tactics of combat during the war, including:
 * Box barrage
 * Chinese barrage
 * Clock method of calling fall of shot
 * Creeping barrage
 * Sound-ranging developed in United Kingdom by Lawrence Bragg