"Sergeant Rayker" was a strip that ran in Warlord about a black sergeant, Moses Rayker, in the US army (and military police) during World War II, who distinguishes himself as a soldier but has to face racism from some of his comrades. The series began in issue 232 (3 March 1979) and last appeared in 1984. Gifford says it was drawn by Salinas, perhaps Alberto Salinas or Magallanes Salinas (whence comes this convention of identifying foreign artists only by surname?), but episodes scanned online are clearly the work of Mike Dorey.
The series was reprinted under the title "Black Boy" in the French Comic Bengali in 1983-85.