Grass Valley Public Library in California
The state of California has an impressive 142 Carnegie libraries, including this one in Grass Valley, which is still in operation today. Carnegie donated $15,000 for this building, which was designed by William Mooser in neoclassical style (also known as revival style) and opened to the public in 1916.
Today, this particular library is known as the Royce Branch, and it's part of the Nevada County Library System. The historic building is also on the National Register of Historic Places.