USS Mahopac, a 2100-ton Canonicus class monitor built at Jersey City, New Jersey, was commissioned in September 1864. During the latter part of 1864, she mainly served on the James River, where she engaged a Confederate battery at Howlett's Farm on 5-6 December. Later in that month, she steamed down the North Carolina coast to take part in the initial attempt to capture Fort Fisher and thus close off blockade running into the port of Wilmington. That effort failed, but Mahopac returned on 13-15 January 1865 with a large Federal fleet and land force that overwhelmed the powerful fortification.

After spending a few months off Charleston, South Carolina, Mahopac returned to the James River area, where she assisted in the capture of Richmond in April 1865. With the Civil War at an end, she was out of commission at Washington, D.C., in 1865-66. Returning to active duty in the latter year, Mahopac served along the east coast for more than a decade, including some time in decommissioned status. She was renamed Castor in June 1869 but regained her original name less than two months later. The monitor was kept in the James River vicinity, possibly including some time on active service, during 1877-1895. USS Mahopac was then laid up at Philadelphia'a League Island Navy Yard until March 1902, when she was sold.

This page features all the views we have related to USS Mahopac.

Photo #: NH 59428 USS Mahopac (1864-1902) Officers on deck, probably on the James River in the spring of 1865. Note gun port covers hung on the monitor's turret, apparent shot hole in the bullet-proof iron screen at the turret top, and bell on the turret side. Photographed by the Matthew Brady organization. The original negative is # 111-B-418 in the National Archives.

The following depictions of USS Mahopac show her distantly or partially, as an element in a view that is mainly of another subject:

Photo #: 111-B-80 Federal ironclads in Trent's Reach, James River, Virginia Photographed circa early 1865. Nearest ship is USS Saugus, with a mine sweeping "torpedo rake" attached to her bow. Next monitor astern is probably USS Sangamon. Visible just to the right of her is either USS Mahopac or USS Canonicus. Last two ships are USS Atlanta and USS Onondaga. Photographed by the Matthew Brady organization. Note the log boom across the river in the foreground and the signal tower atop the hill in the right distance. Photograph from the Collections of the U.S. National Archives.
Photo #: NH 1473-A Washington Navy Yard, District of Columbia View looking south from Building # 1, showing the trophy gun park in the foreground, with coal piles and the sheer crane beyond, circa 1866-69. Most of the guns visible are former Confederate pieces, many of which were still on exhibit at the Washington Navy Yard in the year 2001. The monitors Mahopac (center) and Saugus (right) are laid up in the Anacostia River, in the background, with their turrets still painted as they were in 1864-65. Courtesy of Robert A. Truax, 1978. A stereo pair version of this image is available as Photo # NH 1473-B Online Image of stereo pair: 72KB; 675 x 355 pixels
Photo #: NH 93868 Washington Navy Yard, District of Columbia Four monitors laid up in the Anacostia River, off the Washington Navy Yard, circa 1866. Ships are (from left to right): USS Mahopac, USS Saugus, USS Montauk (probably); and either USS Casco or USS Chimo. Photo mounted on a stereograph card, marked: "Photographed and published by Kilburn Brothers, Littleton, N.H.". Courtesy of Paul H. Silverstone, 1982. A stereo pair version of this image is available as Photo # NH 93868-A Online Image of stereo pair: 47KB; 675 x 370 pixels
Photo #: NH 57928 Washington Navy Yard, D.C. View looking eastward along the waterfront from atop the roof of the western shiphouse, June 1866. The 11th Street bridge and the Anacostia shore are in the distance. Ships in the stream at right include three monitors and a former Confederate torpedo boat of the "large David" type. Monitor to the left in that group is either Chimo or Casco. The other two are Mahopac (center of group) and Saugus (to right). The ex-CSS Stonewall is anchored in the river, in the center of the view. Half visible on the marine railway (at left) is a "double-ender" gunboat, probably USS Ascutney. Dismasted screw steamer alongside the waterfront in center may be USS Marblehead. Ship in right foreground, alongside the masting sheers, may be USS Resaca. The experimental firing battery is just beyond the shiphouse, in the left center foreground, flanked by what appears to be a ship's smokestack on one side and a mortar and a shot pile on the other. Photographed by Brady & Company, Washington, D.C.
Photo #: NH 42241 Fort Fisher operation, December 1864 -- January 1865 Lithograph by Endicott & Company, New York, circa 1865, entitled "Monitor Iron-Clads and the New Ironsides, Forming part of the Fleet of Rear Admiral D.D. Porter, U.S.N. riding out a Gale of Wind, at Anchor off Fort Fisher, Coast of North Carolina, December 21, 1864." The print is dedicated by the publisher to Assistant Secretary of the Navy Gustavus V. Fox. Monitors in the foreground and middle distance are (from left to right) Monadnock (twin-turret), Canonicus, Mahopac and Saugus. Ships in the distance (from left to left-center) are: Brooklyn, New Ironsides, Juniata, Tacony and Malvern. Collection of President Franklin D. Roosevelt, April 1936.
Photo #: LC-USZ62-144 "Bombardment of Fort Fisher" "Jan. 15th 1865" Lithograph after a drawing by T.F. Laycock, published by Endicott & Co., New York, 1865, depicting the North Atlantic Blockading Squadron bombarding Fort Fisher, North Carolina, in preparation for its capture. The print is dedicated to Commodore S.W. Godon, USN. Ships present, as named on the original print, are identified in Photo Number LC-USZ62-144 (Complete Caption). Collections of the Library of Congress.
Photo #: NH 42240 Fort Fisher operation, December 1864 -- January 1865 19th-Century painting, by an unidentified artist, depicting U.S. Navy ironclads bombarding Fort Fisher during one of the two assaults that ended in its capture. Twin-turret monitor in the center foreground is Monadnock. Large broadside ironclad beyond is New Ironsides. The three single-turret monitors are Canonicus, Mahopac and Saugus. Presented by Albert Rosenthal, January 1935.
Photo #: NH 59170 "Second Attack upon Fort Fisher, showing the positions of the vessels, and the lines of fire", 13-15 January 1865 Chart by Walter A. Lane, published in "The Soldier in our Civil War", Volume II. The positions of 58 ships are represented on the chart. Online Image: 216KB; 825 x 1225 pixels