The pilot reported that he returned to the traffic pattern after a 45-minute flight in the amateur-built, World War I replica airplane. During the landing touchdown, the airplane bounced once and veered to the left. The pilot reported that “the aircraft traveled sideway for 50 – 75 feet.” The landing gear “folded” and the left wing sustained substantial damage. The pilot reported that he had about 10 hours of flight time in the airplane, and that the airplane was a “delight to fly” but the landings were always “tricky.” The inspection of the airplane did not reveal any evidence of pre-impact failure or malfunction.