PHINEAS TAYLOR P.T. BARNUM (1810-1891). Barnum was an American showman and businessman in the entertainment industry. He is best known as the co-founder of Barnum & Bailey Circus.ALS. 1pg. February 5, 1861. New York. An autograph letter signed P. T. Barnum: Dr. Sir, Mr. Greenwood has all the proper arrangements about free tickets with Mr. Hinchman. Barnum wrote on letterhead of Barnums American Museum, the museum/zoo/performance hall that he owned from 1842 until it burnt down in 1865. The entire left margin of the sheet advertises the museums varied and sensationalized attractions. The letter is in fine condition.