Action Comics #45 sees Superman saying good-bye to his old secret idenity as Clark Kent in favour of a new one — Archie Clayton.
In Action Comics #43 the world learnt the secret identity of Superman aka Clark Kent — thanks to Lois Lane. She figured it out and noticed that he was wearing a Superman uniform under his shirt and tie. This set of a number of events — Supes going into hiding, being fired from the Daily Planet and, of course, being persecuted by the U.S. Government. Now he is back, but he in a way we’ve never seen him before. Clark Kent is now Archie Clayton, a truck driver.