About 23,000 casualties were suffered at the Civil War battle of Pittsburg Landing, also known by what name?

Which man was both the 22nd and 24th president of the United States? Which author wrote 23 small books for children, including "The Tale of Tom Kitten"? In biological classification, which rank does the name "Homo sapiens" represent? 23 years after the United States did so, Brazil abolished what in 1888? The presidential library at 2313 Red River Street in Austin, Texas, is dedicated to which president? Casino magnate Sheldon Adelson opened his $1.9 billion Palazzo resort in which city in 2007? What is the 23rd letter of the 24-letter Greek alphabet? Which actor is the father of "24" star Kiefer Sutherland?