I'm sure there were spurs like that before the Civil War, and I imagine there were lots of them available as surplus after the Civil War. They would have also been used until the end
of the use of horses in the military. I was typing this answer, and got a wild idea, and googled George Washington spurs, and low and behold I got this from the Mt. Vernen Museum.

These spurs are likely similar to the "fashionable" ones George Washington requested and received during the winter of 1780-1781. The fact they are
unmarked suggests their manufacture by English makers who specialized in riding equipment sold in the colonies as ready-made goods.
During the army's trying winter encampment at Valley Forge, Washington inspired his men through simple gestures. These included giving the spurs on
his boots to Lieutenant Thomas Lamb, who volunteered to ride to Boston to request supplies. Unfortunately, Lamb and his horse were injured near the city.
Lamb delivered Washington's message, but was prevented from further active duty and discharged in 1779.
Only, the spurs pictured are made of silver. Man, if I found a spur made of silver I probably die of a heart attack. Looks like you are in a good spot, so keep looking for the
silver one.