NASHVILLE (AP) - Merle Haggard will be honored for his 50 years in country music at the Academy of Country Music Awards. Haggard will receive the ACM Crystal Milestone Award at the ceremony on April 6 in Las Vegas. He was the ACM's first Entertainer of the Year in 1970. Haggard will also be the subject of a tribute album, featuring remakes of his songs by Garth Brooks, Thompson Square, Jason Aldean, Dierks Bentley, Luke Bryan and Toby Keith, among others. "Working Man's Poet: A Tribute To Merle Haggard" comes out April 1.