South Carolina man gets 1-year sentence in immigration case   © 2008 The Associated Press   JACKSON, Miss. — A South Carolina man has been sentenced to a year in prison on charges of flying illegal immigrants between Texas and South Carolina.   U.S. Attorney Dunn Lampton said James Leroy Pierson was sentenced Monday in U.S. District Court in Jackson. Pierson had pleaded guilty to the charge in March.   Prosecutors said customs agents tracked Pierson's plane when it left McAllen, Texas, on January 28 with a destination of Clemson, S.C. When the plane landed in Meridian, Pierson and four passengers were taken into custody.   Custom agents said the passengers admitted to being illegal immigrants.