Beginning with the lighting of the Fort Gratiot Light in 1825, and continuing until 1983, when the last manually operated lighthouse in Michigan was automated, lighthouse keepers kept the lights lit each night.

Things that I remember most about his duties were, there seemed to always be a paintbrush in his hand. ….. The government put great stock in painting. They painted and they repainted and they painted, until paint usually built up so it had so many coats there were no sharp edges at all anymore. 

James F. Sheridan

For most of the nineteenth-century keepers were political appointees. Generally, the local collector of customs nominated an individual to the Secretary of the Treasury, who formally appointed each keeper. 

The collector of customs, also a political appointee, most often used keeper nominations to repay political favors. Until the 1850s this system of appointment stymied all efforts to reform the service and establish a merit appointment system. Slowly, however, various reforms were put in place that limited the range of political appointments.

By the 1870s the Lighthouse Board, which then was responsible for the operation of all lighthouses in the U.S., had established basic characteristics that keepers must possess. 

Newly appointed keepers should be between the ages of eighteen and fifty.  A keeper should be able to read and write, keep simple financial accounts, be able to pull and sail a boat, and possess sufficient skill to maintain the equipment and perform minor repairs. (Source: cmich.edu)