The utilitarian reference by Rusty Goe titled The Mint on Carson Street allows the following concerning 1875 eagle mintage:   'For unknown reasons, there were fewer $10 eagles produced at the nation's mints in 1875 than in any year after the Civil War. For the first time since it opened in 1854, the San Francisco Mint did not strike any gold eagles, and Philadelphia delivered an all time low of 120 pieces, 20 of which were Proofs, leaving Carson City as the leader for the year with a whopping 7,715 eagles minted.'       

Today the 1875-CC eagle is extremely challenging, even measured by the already-difficult yardstick of CC-mint tens. Of the paltry original mintage, Goe estimates that a mere 95-115 coins survive in all grades.