After six weeks of continuous bombing, shelling, and fighting, the men of the VI Corps were as exhausted as their German adversaries. Following the collapse of the final enemy drive on 4 March, a three-month lull began. During this time both armies limited their operations to defending the positions they held at the beginning of March, while they conducted limited counterattacks and raids and marked time until the renewal of offensive operations on the southern front. Although the reinforced Fourteenth Army, totaling 135,698 troops by 15 March, considered another offensive, plans were shelved in early April in favor of conserving troop strength to counter an expected Allied spring offensive.
During March, all of April, and the first part of May 1944, recalled one veteran, the Anzio beachhead resembled the Western Front during World War I. The vast majority of Allied casualties during this period were from air and artillery attacks, including fire from "Anzio Annie," a 280-mm. German railway gun which fired from the Alban Hills. During March, shrapnel caused 83 percent of all 3d Division casualties, and other units experienced similar rates. The Anzio beachhead became a honeycomb of wet and muddy trenches, foxholes, and dugouts. Yet the Allied troops made the best of a bad situation, and one soldier recalled that during these months the fighting was light and living was leisurely.
On the night of 11-12 May, the Fifth and Eighth Armies launched their long-awaited spring offensive against the Gustav Line. Stymied in attempts to break through at Cassino in February, March, and April, the Allies initially encountered little success in their new drive. Nonetheless, the Germans abandoned Monte Cassino after a week of heavy fighting by Polish forces, and the French Expeditionary Corps and U.S. II Corps succeeded in breaking the Gustav Line by 15 May. The II Corps continued its drive north toward Terracina, which fell on 23-24 May, and raced toward the Anzio beachhead against rapidly crumbling German resistance as enemy troops began withdrawing northeast toward Rome.
At 0545, 23 May, a 45-minute Allied artillery barrage opened on the Cisterna front, followed by armor and infantry attacks along the entire line from Carano to the Mussolini Canal. Although resistance was very stiff, by evening the 1st Special Service Force and 1st Armored Division had breached the enemy main line of resistance, while the XII Tactical Air Command completed the last of 722 sorties. The following day VI Corps forces cut Highway 7 above Cisterna and encircled the town, the scene of continued heavy fighting by desperate enemy forces. The town finally fell on 25 May at the cost of 476 Americans killed, 2,321 wounded, and 75 missing.
Earlier on 25 May, at 0730, troops of the 91st Reconnaissance Squadron, 85th Infantry Division, U.S. II Corps, racing north from Terracina across the Pontine Marshes, met soldiers of the 1st Battalion, 36th Engineer Combat Regiment, from the Anzio beachhead, effecting the long-planned and longer-awaited link-up between Fifth Army forces. With the physical juncture of the II and VI Corps, the beachhead ceased to exist and the formerly isolated soldiers became the left flank of the Fifth Army. Clark personally greeted the II Corps troops three hours later.
Meanwhile, the breakout west was proving costly to the VI Corps. The 1st Armored Division lost 100 armored vehicles in the first day alone, while the entire corps took over 4,000 casualties in the first five days of the offensive. Allied troops, however, counted 4,838 enemy prisoners, including 1,000 in Cisterna, and destroyed or damaged 2,700 enemy vehicles.
On the same day that the Fifth Army front merged with the Anzio beachhead, General Clark also split Truscott's forces into two parts, sending the 3d Division, the 1st Special Service Force, and elements of the 1st Armored Division toward Valmontone. This thrust, however, proved insufficient, and most of the Tenth Army escaped north to fight again. In the meantime the 45th and 34th Infantry Divisions, along with the rest of the Fifth Army, joined in the hot pursuit of German forces falling back on Rome, a scarce thirty miles distant. Americans liberated the Italian capital on 4 June 1944.
During the four months of the Anzio Campaign the Allied VI Corps suffered over 29,200 combat casualties (4,400 killed, 18,000 wounded, 6,800 prisoners or missing) and 37,000 noncombat casualties. Two-thirds of these losses, amounting to 17 percent of VI Corps' effective strength, were inflicted between the initial landings and the end of the German counteroffensive on 4 March. Of the combat casualties, 16,200 were Americans (2,800 killed, 11,000 wounded, 2,400 prisoners or missing) as were 26,000 of the Allied noncombat casualties. German combat losses, suffered wholly by the Fourteenth Army, were estimated at 27,500 (5,500 killed, 17,500 wounded, and 4,500 prisoners or missing)—figures very similar to Allied losses.
The Anzio Campaign continues to be controversial, just as it was during its planning and implementation stages. The operation clearly failed in its immediate objectives of outflanking the Gustav Line, restoring mobility to the Italian campaign, and speeding the capture of Rome. Allied forces were quickly pinned down and contained within a small beachhead, and they were effectively rendered incapable of conducting any sort of major offensive action for four months pending the advance of Fifth Army forces to the south. Anzio failed to be the panacea the Allies sought. As General Lucas repeatedly stated before the landing, which he always considered a gamble, the paltry allotments of men and supplies were not commensurate with the high goals sought by British planners. He steadfastly maintained that under the circumstances the small Anzio force accomplished all that could have been realistically expected. Lucas' critics charge, however, that a more aggressive and imaginative commander, such as a Patton or Truscott, could have obtained the desired goals by an immediate, bold offensive from the beachhead. Lucas was overly cautious, spent valuable time digging in, and allowed the Germans to prepare countermeasures to ensure that an operation conceived as a daring Allied offensive behind enemy lines became a long, costly campaign of attrition.
Yet the campaign did accomplish several goals. The presence of a significant Allied force behind the German main line of resistance, uncomfortably close to Rome, represented a constant threat. The Germans could not ignore Anzio and were forced into a response, thereby surrendering the initiative in Italy to the Allies. The 135,000 troops of the Fourteenth Army surrounding Anzio could not be moved elsewhere, nor could they be used to make the already formidable Gustav Line virtually impregnable. The Anzio beachhead thus guaranteed that the already steady drain of scarce German troop reserves, equipment, and materiel would continue unabated, ultimately enabling the 15th Army Group to break through in the south. But the success was costly.