The correct answer is A. Free verse. Sandburg was inspired to write it one day while walking near Chicago's Grant Park. He was inspired by Japanese Haiku poems. Carl Sandburg wrote a lot of poetry throughout his life and was also a collector of American folk songs. He wrote a biography of Abraham Lincoln. "Fog" is a poem that reflects Sandburg's interest in the natural world and captures a moment when the fog came moving over harbor waters, given life through a metaphorical cat.