Belgian Soldiers Guarding a Checkpoint Near Halen, Belgium (1914)

Belgian soldiers guarding a checkpoint near Halen, Belgium, shortly after the German invasion of Belgium, August 1914.

Source.

View of Militiamen of the Lexington Light Infantry on Parade in the Cheapside Section of Lexington, Kentucky (1850′s)

View of militiamen of the Lexington Light Infantry on parade in the Cheapside section of Lexington,

Kentucky, c. 1850′s.

Source.

Union Musicians from the 9th Regiment of the Veteran Reserve Corps Posing With Their Instruments and a Scruffy Dog at Washington Circle in Washington, D.C. (1865)

Union musicians from the 9th Regiment of the Veteran Reserve Corps posing with their instruments and a scruffy dog at Washington Circle in Washington, D.C., April 1865.

Source.

A Group of What Are Believed to be French Zouaves and Chasseurs Posing for the Camera at an Unidentified Location (1860's)

A group of what are believed to be French Zouaves and chasseurs posing for the camera at an unidentified location, c. 1860's.

Source.

Thanks to Gary Dombrowski and members of Civil War Talk for pointing out that these are probably French troops.

Portrait of Officers and Non-Commissioned Officers From Company F of the 8th Regiment New York State Militia

Portrait of officers and non-commissioned officers from Company F of the 8th Regiment New York State Militia, c. 1850′s. From Miller's Photographic History of the Civil War.

Militiamen of the 1st Regiment, Missouri State Guards, Posing at Camp Lewis Which Was Set up on Fair Grounds in St. Louis, Missouri (1860)

"Camp Lewis, 1st Regiment, Missouri State Guards, Col. A. R. Easton, St. Louis Fair Grounds. Salted Paper Print, 1860." Militiamen of the 1st Regiment, Missouri State Guards, posing at Camp Lewis which was set up on fair grounds in St. Louis, Missouri, 1860.

Source.
More information.

A Military Band Playing For a Group of Civilians at Curragh Camp in County Kildare, Ireland (1861)

A military band playing for a group of civilians at Curragh Camp in County Kildare, Ireland, 1861. Attributed to Edward Dyne Fenton.

Source.

Union Soldiers of the 22nd Regiment New York State Militia Posing in Camp Near Harpers Ferry, Virginia (1862)

Union soldiers of the 22nd Regiment New York State Militia posing in camp near Harpers Ferry, Virginia, c. 1862. Attributed to Mathew Brady.

Source.

British Soldiers Posing Having a Mock Skirmish (1861)

British soldiers posing having a mock skirmish, 1861. By Edward Dyne Fenton.

Source.

Staged Photograph of a French Corporal Waking Up His Men at Camp de Châlons, France (1857)

Staged photograph of a French corporal waking up his men at Camp de Châlons, France, 1857.

Source.

French Soldiers Eating in Camp at St. Maur, France (1859)

French soldiers eating in camp at St. Maur, France, 1859. By the Gaudin brothers. Animated stereoview.

Source.