The pilot and flight instructor were completing an instructional flight in the tailwheel airplane that the pilot recently purchased. The pilot had completed 8 uneventful takeoffs and landings. During the final landing roll with a slight right crosswind, the airplane veered to the right. The pilot attempted to correct with opposite rudder but was unable to maintain directional control. The airplane exited the right side of the runway and ground looped, which collapsed the left main landing gear and resulted in substantial damage to the left wing and left horizontal stabilizer. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. The flight instructor did not report any attempt in remedial action during the accident sequence.