Senate "credentials" for Tristam Dalton, signed by John Hancock

This certificate of election, or credentials, was signed by John Hancock for Tristram Dalton, a Senator for Massachusetts. After a new Senator was chosen by the state legislature, a formal certificate was submitted to be signed by the state governor. In 1789, John Hancock—whose name now means “signature”—was Governor of Massachusetts and signed the credentials. Each Congressman presented his credentials when reporting to Congress.

National Archives, Records of the U.S. Senate