The Navy's FY2011 budget proposes canceling the CG(X) program as unaffordable and instead building an improved version of the Arleigh Burke (DDG-51) class Aegis destroyer called the Flight III version. This report provides background information on the CG(X) program as it existed prior to its proposed cancellation. For further discussion of the proposal to build Flight III DDG-51s in lieu of CG(X)s, see CRS Report RL32109, Navy DDG-51 and DDG-1000 Destroyer Programs: Background and Issues for Congress.