Md. Code, General Provisions § 6–104

(a) Condemnation of private property by the United States shall be in accordance with Title 12 of the Real Property Article.

(b) (1) Except as provided in paragraph (2) of this subsection, this subtitle does not authorize condemnation of any tract of land that exceeds 10 acres.

(2) The United States may condemn a tract of land that exceeds 10 acres to build an arsenal, a coastal defense, a fort, or a magazine, including a barracks for staff.