Here is the Detroit and Cleveland Navigation Line's City of Cleveland by day and by night. The side wheel steamer was destroyed by fire shortly after it was built in 1907, but was rebuilt again by 1908. The Great Lakes steamer transported passengers between Detroit and Cleveland.
Here are the backs of the cards. I posted the second one first, because it has a message and some interesting cancellation stamps. The sender seems to have thought that a one cent was sufficient postage for a card from Detroit, Michigan to Mainz, Germany. It looks like it arrived postage due. I don't know enough about postal history though to be able to tell you why the amount stamped on it is 10 centimes instead of an amount in German pfennigs.
Here's the back of the first card.