Postmarked Oct. 1, 1908
This was the second U.S. Mint built. It was built between 1829 and 1833 on the Northwest corner of Chestnut and Juniper Streets in Philadelphia. It replaced the first U.S Mint that was built in 1792. The second Mint was in operation till 1901 and was demolished by 1903. You can see city hall behind the Mint in the postcard image above.