How did Charles Sanders Peirce begin working for the U.S. Coast and Geodetic Survey?

Charles Sanders Peirce began his association with the U.S. Coast and Geodetic Survey in 1859, when he spent one year working with the organization's field parties after graduating from Harvard College.1

He later reentered the Survey in 1861 to serve as a computing aide to his father, Benjamin Peirce. In this role, he assisted his father in the task of determining the longitudes of American survey points relative to European ones by observing lunar occultations of the Pleiades. Much of this early astronomical work was conducted at the Harvard Observatory.1