Calling card of Dana W. Hall of East Dixfield, Maine; nothing on reverse.
From brief online research, hopefully correct - corrections and additions requested:
Odds are that this was the calling card of Dana Warren Hall, born April 4, 1866 at Wilton, Maine, son of Warren W. Hall and Eliza A. (Morse) Hall. By 1900, Dana was living at Chicago, Illinois, and working as a Solicitor (Books), whatever that meant, and was still working in the publishing industry at the time of the 1910 Census of Chicago. In the 1920 Census of Chicago, he gave his occupation as publisher.
On April 2, 1910 in Chicago, Illinois, Dana Warren Hall married Imogene Donovan, who was born in Connecticut, daughter of Timothy Donovan and Imogene A. (Ferry) Donovan.
Dana died in 1926 in Chicago, Illinois, and is buried in the East Dixfield Cemetery at Wilton, Maine, in the plot of William D. Adams, according to the Nathan Hale Cemetery Collection, Maine, ca 1780-1980. Imogene outlived him and subsequently married Franklin Winslow Johnson, president of Colby College at Waterville, Maine, from 1929-1942.
If you have additional information, or if you feel that Dana W Hall of East Dixfield, Maine, is a different person, please leave a comment or contact me directly.