The Military Order of the Loyal Legion of the United States still exists. It was made a hereditary organization after the war and is open to the male descendants of Union commissioned officers (and the siblings of such officers). I was its national Commander-in-Chief in 1993-1995.

This photo prompted me to go and read about François d'Orléans, Prince of Joinville. He was a fascinating character -- accomplished artist, fought in numerous battles as a naval officer in Europe, came to America to fight for the Union in the Civil War, then back to France for more adventures.

Prince Robert Philippe Louis Eugène Ferdinand of Orléans, Duke of Chartres (November 9, 1840 – December 5, 1910) was the son of Prince Ferdinand Philippe, Duke of Orléans, and thus grandson of King Louis-Philippe of France. He fought for the Union in the American Civil War.

With the outbreak of the American Civil War in April 1861, Chartres and his brother, Prince Philippe, Count of Paris, travelled to the United States to support the Union cause. On September 24, 1861, Chartres was commissioned a captain in the United States Army. He served as an assistant adjutant general on the staff of the commander of the Army of the Potomac, Major General George B. McClellan. He served in the Battle of Gaines's Mill on June 27, 1862 and resigned from the Union Army on July 15, 1862.

During their stay in the United States, the princes were accompanied by their uncle, the Prince of Joinville, who painted many watercolours of their stay. Although eligible for membership, Chartres did not join (as his brother had) the Military Order of the Loyal Legion of the United States – an organization of Union officers who had served during the American Civil War.

Wikipedia

They are captioned as at Camp Winfield Scott. My friend Scotty Moore was Elvis' original guitarist. His real name was Winfield Scott Moore III. He was born (and buried) in Gadsden, TN. I asked him once why three generations of his family were named for a Yankee General. He replied, "they must have run out of names." Actually there were two, a U.S. General Winfield Scott who was born in Virginia and died in 1865 and a General Winfield Scott Hancock from the Civil War. My guess would be they were named for the former. Both were loyal to the North. The latter was actually named for the former who was also a general in the War of 1812.