R&B diva Mariah Carey will join retired Army Gen. Colin Powell and others in Washington, D.C. next week to receive a Congressional Award in honor of her contributions to youth charities and nonprofit organizations.Carey will be recognized for her work with the Fresh Air Fund and the Administration for Children's Services in New York City. The singer has donated over a $1 million to the Fresh Air Fund and its Awareness Camp, which assists youth in education and career planning. She has also participated in Children's Services' programs to ensure that kids are raised in a stable family environment. Carey will receive a 1999 Horizon Award during a gala ceremony scheduled for April 21 at the Ronald Reagan International Trade Center. The dinner and awards presentation will be attended by several congressional leaders, including Sen. Trent Lott and Rep. Dick Gephardt. Powell and Discovery Communications' Judith McHale will each receive Leadership Awards for their respective work in encouraging volunteerism and community involvement by America's youth. The Congressional Award Foundation was formed in 1979 to help promote personal development and exploration for those between the ages of 14 to 23, and its award is only one of two (the other being the Medal of Honor) legislated by a Congressional Act.