An original albumen carte-de-visite photograph depicting the combat guidon of Battery M, 2nd United States Regular Artillery. The flag features crossed cannons with a centralized 1st U.S. overlay insignia, flanked by a prominent M and 2. A vast, sprawling array of painted battle honors covers nearly the entirety of the flag's quadrants.

The reverse features a rare, early small oval backmark for Gardner, Corner 7th & D Str., Washington, D.C. It bears a superb period ink presentation inscription: "Compliments of / Alex. Pennington / 1st Lieut. 2d U.S. / Comdg. Battery M." Modern pencil notation at the left margin tracks its exceptional institutional lineage: "from Alexander Stewart Webb album."

This card stands as a spectacular historical crossroads, directly linking an elite, battle-hardened regular army artillery unit with two of the most famous Union generals of the Eastern Theater. The guidon proudly displays a sprawling timeline of Regular Army service across multiple theaters, featuring meticulously painted battle honors that include Antietam and Gettysburg. 

Battery M, 2nd U.S. Artillery operated as a premier horse artillery unit assigned to the Cavalry Corps of the Army of the Potomac. Lieutenant Alexander Cummings McWhorter Pennington Jr. (1838–1917), a West Point graduate, took command of the battery in 1862. Pennington and his artillerymen famously served under General Custer's brigade, playing a decisive role at Gettysburg on 3 July 1863, where their precise, rapid counter-battery fire on East Cavalry Field helped shatter J.E.B. Stuart's flanking assault. This card was presented by Pennington directly to his fellow regular officer and close associate, Alexander Stewart Webb. Webb, of course, is the legendary, Medal of Honor-winning commander of the Philadelphia Brigade who famously held the Angle against Pickett's Charge at Gettysburg. He likely cherished this carte. 

The piece transcends a standard unit record; it is a personal token of mutual respect shared between Alexander Pennington and Alexander Stewart Webb, two men who stood at the absolute epicenter of the turning point of the war. It represents an institutional-grade piece of the utmost rarity.

[Photography, Early Photography, Historic Photography, Daguerreotypes, Ambrotypes, Tintypes, Cased Images, Union Cases, Albumen Photographs, CDVs, Carte de Visites, Cartes de Visite, Carte-de-visite, Cartes-de-visite, CDV, Cabinet Cards, Stereoviews, Stereocards, Stereographs] [Civil War, Union, Confederate]

Excellent. The albumen print retains exceptional crispness and strong contrast. The mount is structurally pristine with clean borders.