Complex sentence: Hamburg (1895--1915) was an American Thoroughbred race horse bred in Kentucky by James E. Kittson, brother to Norman W. Kittson who had been partners in Erdenheim Stud.
Split into simpler sentences: Hamburg (1895--1915) was an American Thoroughbred race horse. Hamburg was bred in Kentucky by James E. Kittson, brother to Norman W. Kittson who had been partners in Erdenheim Stud.