The estate in Howard County where the descendants of Charles Carroll, a signer of the Declaration of Independence, still live could be sold for a retirement community and preserved with the County Council’s approval.

Camilla and Philip Carroll, owners of Doughoregan Manor in Ellicott City, signed a deal with Erickson Retirement Communities to build a continuing-care community on about 150 acres of the 892-acre estate, which is a national landmark, said family spokesman Brad Phillips this week.