critically all the works, completed, under construction, and projected.
The findings of the board were, in brief, as follows:
That there were (in December, 1862) surrounding Washington
, fifty-three forts and twenty-two batteries; that the perimeter of the entire line of fortifications was thirty-seven miles; that the armament consisted of six hundred and forty-three guns and seventy-five mortars; that the total infantry garrison needed for a proper manning of the defenses was about twenty-five thousand; that the total artillery garrison necessary was about nine thousand, and that a force of three thousand cavalry was necessary to make reconnaissances in order to give warning of the approach of the foe. In accordance with the recommendations of the board, Congress raised the embargo on funds for further defense preparation, and, during 1863, several important new works were opened and completed, and the old ones kept in a high state of efficiency.
One of the most notable new works was Battery Rodgers at Jones' Point
, near Alexandria
, for defense against the Confederate vessels.
During 1864, one large fort, McPherson
, was commenced on the Virginia
side between Long Bridge
and Aqueduct Bridge but not completed, and some smaller ones built.
With these exceptions the time was devoted to keeping in good repair those already constructed.
These included some water batteries that had been constructed in 1862 as a supplementary aid to the forts in repelling naval attacks.
The amount of work that was expended on the defenses of Washington during the war was indicated by the fact that, at the close of the war, in April, 1865, the fortifications consisted of sixty-eight enclosed forts and batteries, whose aggregate perimeter was thirteen miles, eight hundred and seven guns, and ninety-eight mounted mortars, and emplacements for one thousand one hundred and twenty guns, ninety-three unarmed batteries for field-guns, thirty-five thousand seven hundred and eleven yards of rifle-trenches, and three blockhouses.