• Type: Cut Down 7.5-inch Blakely Rifle,
  12 hook-slant Rifle Grooves
• Tube Composition: Cast Iron
• Bore Diameter: 7.5 inches
• Tube Length: 100 inches (originally 124 inches)
• Markings: (Breech Band) BLAKELY'S PATENT 1861. (Left Trunnion) LOW MOOR 1861. (Trophy No. Plate) 170
• West Point Trophy Plaque: CIVIL WAR - 7.5 IN. BLAKELY CAST IRON - RIFLED GUN MADE BY THE - LOW MOOR IRON CO. ENGLAND IN 1861. - CAPTURED FROM CONFEDERATE FORCES - VICKSBURG MISS.
• Current Disposition: Vicksburg, Mississippi
• Special Notes: This 7.5-inch rifle was called the "Widow Blakely" because it was the only specimen of British Captain Theophilus Alexander Blakely's design in the works at Vicksburg.

On May 22, 1863, the "Widow Blakely" was manned by a detachment of Company 'H', 1st Louisiana Heavy Artillery, commanded by Lieutenant A. L. Slack. On that day the Widow, mounted overlooking the Mississippi River, engaged four iron-clads and one wooden gunboat with the help of nine other guns, helping to heavily damage two of the ironclads, and repulse the rest of the attacking force. However, in that day's action one of the Widow's shells exploded in the tube while it was firing at a Union gunboat. The explosion took part of the end of the muzzle off, leaving the remainder of the tube intact. The ragged ends were cut smooth and the rifle was used as a mortar during the rest of the siege.

After the trimming of the muzzle the overall length of the barrel is about 100 inches. Originally the tube would have been about 124 inches long.

After Union forces captured Vicksburg, the Widow was taken to the U.S. Military Academy at West Point and displayed as a trophy for ninety-six years, the Widow was misidentified as "Whistling Dick", another famous Confederate cannon. When her true identity was recognized, the Widow was sent back to Vicksburg, the Park Service mounting her on the bluffs about a mile south of her original position. This cannon has also been misidentified as a 7.44-inch caliber rifle. Measurements of the lands, nearly 1.5 inches wide, show diameters between 7.50 and 7.51 inches.