what was most likely reason that healthy first and second-class passengers were admitted to the U. S. without being processed at Ellis Island, while those in steerage had to go through processing?

Ellis Island is a place where most European immigrants were processed when coming into New York Harbor. Here, they had to prove that they were healthy, had money, a skill or someone to sponsor them and provide for them. While first and second class passengers were inspected on the ship, all steerage passengers came through Ellis Island. Steergate passangers were considered to be less wealthy, with no one to vouch for them, possibly criminals or with cloudy past.