PHOENIX (Reuters) - U.S. immigration agents have arrested 595 people at a Mississippi factory in what was the largest workplace enforcement raid in the United States to date, an immigration official said on Tuesday. Immigration and Customs Enforcement spokeswoman Barbara Gonzalez said federal agents arrested the workers in a raid at the Howard Industries Inc. factory in Laurel, Miss, on Monday, "This is the largest targeted workplace enforcement operation we have carried out in the United States to date," Gonzalez told Reuters by telephone. The swoop at the plant, which makes electrical equipment including transformers, was part of an ongoing...