Youngstown's industrial development made the Mahoning Valley different. The community's coal industry made hundreds of immigrants from Wales, Germany, and Ireland come to the area. With the start of steel mills in the late 19th century, Youngstown became a popular destination for immigrants from Eastern Europe, Italy, and Greece. In the early 20th century, the community saw more immigrants from non-European countries including what is today's Lebanon, Israel, and Syria. By the 1920s, this change in the town's population made people who were there earlier upset. Because of their anger, the Mahoning Valley became a center of Ku Klux Klan activity. The situation reached a climax in 1924, when street clashes between Klan members and Italian and Irish Americans in neighboring Niles led Ohio Governor A. Victor Donahey to declare martial law. By 1928 the Klan was in steep decline; and three years later, the group sold its Canfield, Ohio, meeting area, Kountry Klub Field.