The two cylindrical brass objects in your photos are late-1800s tent-rope adjusters, at that time called a "tent slip." What you've found was patented by H.B. Thomson on November 30th, 1880. (See the official US Patent diagram, below.) The patent date is marked on ones made during the 17-year life of the Patent. After it expired, they are unmarked, like yours, so yours were made after 1897.
Thomson's tent-slips were adopted for service by the US Army in 1889. (See the copy of the US Quartermaster General's order, below.) As those two documents prove, contradictory to common belief among relic-diggers and dealers, these metal tent-slips are definitely NOT from the civil war era. As additional proof, none are seen in any of the many-many civil war photos showing soldiers at their tents.
The double-loop brass object on the right in your photos is part of a horse's harness called a gag-runner swivel. Yours has been bent out of its original long-oval shape... but you can recognize it in the scan from a 1907 horse-harness catalog, below. These harness swivels have been sold as civil war sword-scabbard hangers, but that is a misidentification.
