Complex sentence: In 1917 one factory in Auburn was producing 75 percent of the world's supply of white canvas shoes; however, after World War II the shoe industry began to decline, and between 1957 and 1961 the largest manufacturers closed their factories.
Split into simpler sentences: In 1917 one factory in Auburn was producing 75 percent of the world's supply of white canvas shoes. However, after World War II the shoe industry began to decline, and between 1957 and 1961 the largest manufacturers closed their factories.