United States campaigns in World War I American entry into World War I resulted in the American Expeditionary Force being engaged in 13 campaigns , during the period 1917 – 1918 , for which campaign streamers were designated . The streamer uses the colors of the World War I Victory Medal ribbon which had a red center with a rainbow on each side of the center stripe and a purple edge . The double rainbow symbolizes the dawn of a new era and the calm which follows the storm . The following inscriptions in white are authorized : Above and the following are taken from " The Army Flag and Its Streamers " , a pamphlet which was originally prepared in 1964 by the Office of the Chief of Military History , in cooperation with the Office of the Chief of Information and the U . S . Army Exhibit Unit , to provide general summaries of each of the campaign ribbons authorized to be displayed on the Army flag . It was subsequently updated by the Center of Military History to add the campaigns from Vietnam . Cambrai , 20 November – 4 December 1917 . The year that America entered the war was marked by near disaster for the Allies on all the European fronts . A French offensive in April , with which the British cooperated , was a failure , and was followed by widespread mutinies in the French armies . The British maintained strong pressure on their front throughout the year ; but British attacks on the Messines Ridge ( 7 June ) , at Ypres ( 31 July ) , and at Cambrai ( 20 November ) failed in their main objective – the capture of German submarine bases – and took a severe toll of British fighting strength . Three American engineer regiments – the 11th , 12th , and 14th – were engaged in construction activity behind the British lines at Cambrai in November , when they were unexpectedly called upon to go into the front lines during an emergency . They thus became the first A . E . F . units to meet the enemy . Montdidier - Noyon , 9 – 13 June 1918 . Ludendorff followed up his stalled Aisne offensive with a small - scale drive in the Montdidier - Noyon sector on 9 June 1918 . Twenty - one German division attacked the French on a twenty - three mile front extending from Montdidier to the Oise River . The French anticipated the assault and contained it after a nine - mile ( 14 km ) penetration by the Germans , counterattacking strongly . The fighting was over by 12 June , and the enemy had little to show for the heavy losses incurred . No large American units were in the immediate vicinity of this action , although the 1st Division at Cantigny was subjected to artillery fire and diversionary raids . Battle of Hamel , 4 July 1918 . In mid - 1918 , to give his troops experience , Major General George Bell , commanding the 33rd Division , agreed to temporarily detach 10 companies of infantry , to complement battle - hardened , but increasingly under - strength , units of the Australian Corps , under Lieutenant General John Monash . The personnel chosen came primarily from the US 131st and 132nd Infantry Regiments . Each platoon from the companies chosen was attached to an Australian company . A difficulty in integrating the 60 - strong US platoons into 100 - strong Australian companies was overcome by reducing the size of each US platoon and sending surplus troops back to battalion reinforcement camps . An attack was scheduled , for propaganda and morale purposes , on Independence Day 1918 , against German 13th Division positions in and around the town of Le Hamel on the Somme . The American platoons were distributed throughout the Australian 4th Division , 6th Brigade and 11th Brigade . The commitment of these companies represented the first time in history that US troops would fight under a foreign commander . However , after General Pershing learnt that American troops had been detached to a foreign army at the platoon level , he ordered the withdrawal of six American companies . According to Australian sources , a few members of those companies disobeyed the order and took part in the battle . Many of the innovative tactics employed by Monash , such as the use of combined arms and creeping barrages illustrated the tactical lessons learnt by Australian troops over the three years preceding . The Allies ' objectives were achieved in 93 minutes . Champagne - Marne , 15 – 18 July 1918 . In the four great offensives that the Rainbow Division had from 21 March to 13 June 1918 the Germans gained considerable ground , but failed to achieve a decisive advantage at any point on the front . Furthermore , success was bought at a price in manpower and material which they could ill afford . Their more than 600 , 000 casualties were irreplaceable , whereas the Allied loss of some 800 , 000 men was soon more than compensated for by new American units arriving at the front in ever - mounting numbers . By July 1918 Allied troops outnumbered German on the Western Front . Other factors also contributed to the decline of German morale , notably the pinch of the blockade and the effectiveness of the Allied propaganda , which was distributed widely by air at the front and in German cities behind the lines . But Ludendorff refused to consider peace negotiations , and planned two more offensives for July which he hoped would bring victory . The first of the new drives was designed to capture Rheims , to make more secure the supply of the Merge salient , and to draw in Allied reserves . The second and larger offensive , destined never to be launched , would strike once again at the British in Flanders . When the two - pronged German assault on either side of Rheims began on 15 July the Allies were prepared for it . Plans for the attack had leaked out of Berlin , and Allied airplanes had detected the unusual activity behind the enemy front . Foch had time to draw up reserves , and Petain , the French commander , skillfully deployed his troops in defense - in - depth tactics . Consequently the German drive east of Rheims fell far short of its objective . The attack west of the city succeeded in pushing across the Marne near Château - Thierry , but was checked there by French and American units . Among the A . E . F . units involved in this action were the 3d , 26th and 28th Divisions , the 42nd Infantry Division , the 369th Infantry Regiment , and supporting elements ( in all about 85 , 000 Americans ) . It was here that the 38th Infantry of the 3d Division gained its motto , " Rock of the Marne . " By 17 July the Champagne - Marne offensive had petered out and the initiative passed to the Allies . The German people had built up great hopes for the success of this Friedensturm ( peace offensive ) ; its failure was a tremendous psychological blow to the whole nation . Ypres - Lys 19 August – 11 November 1918 . That part of the Western Front extending from the English Channel south through Ypres , and thence across the Lys River to the vicinity of Arras , was manned by an army group under King Albert of Belgium composed of Belgian , British , and French armies . In late August and early September the British Second and Fifth Armies , assisted by the American II Corps ( 27th and 30th Divisions ) , wiped out the Lys salient . When the Germans began retiring in the sector south of the Lys in October to shorten their lines , King Albert ' s army group attacked along its entire front . By 20 October Ostend and Bruges had been captured and the Allied left was at the Dutch frontier . In mid - October Pershing dispatched two American divisions – the 37th and 91st – to the French Army of Belgium , at Foch ' s request , to give impetus to the drive to cross the Scheldt ( Escaut ) southwest of Ghent . A general attack began in this area on 31 October and continued intermittently until hostilities ended on 11 November . The 37th Division forced a crossing of the river southeast of Heurne on 2 November and another farther north at the site of the destroyed Hermelgem - Syngem bridge on 10 November . Casualties of the two divisions in these operations totaled about 2 , 600 . From 19 August to 11 November about 108 , 000 Americans participated in the Ypres - Lys Campaign . Vittorio Veneto , 24 October – 4 November 1918 . Late in the war , Americans participated on a limited scale in campaigns in Italy . The 332d Regiment with attached hospital troops was sent from the A . E . F . to the Italian Front in July 1918 for the morale effect which it was hoped that the sight of Americans would have on the Italians . This force of about 1 , 200 men took part in the last great Italian offensive against the Austrians , the Battle of Vittorio Veneto .