According to Hanna's Centennial program, Hanna township was formed in 1861. The earliest settlers on the territory, which is now Hanna township, were Emanuel Metts and his two sons Izaac and Joseph, Nimrod West, Sen Amsterdam Steward, Andrews J. Chambers and his three sons Preston, Obadiah and Andrew, William Tyner, Charles Strong, and Thomas Hunsley. They all came to the township in or prior to 1839. At that time, Hanna township was a part of Starke county and formed part of the township of Van Buren.

The town plat of Hanna was laid out and surveyed in 1858. In 1859, Young's addition was laid off. In 1858 Clark Richards and Charles Fessenden opened the first store at Hanna directly after or at the time of the completion of the railroad to the town. George Denison opened a store on Sept. 1, 1865. The merchants were grain buyers, and Hanna was quite a market for grain.According to a 1932 article in the Laporte Herald Argus the Kankakee marshes, at first an obstacle toward the settling of the town, became later a boon because of their abundant yield of marsh hay, and for years Hanna was an important center for this crop. Businesses were founded on it. The Kankakee river is four miles east of Hanna.

The first library in Hanna was Opened Dec. 1, 1935 in the back room of the Hanna post office and was established by the Culture Club. A book shower was held that netted about two hundred books. Later, the library was moved to a larger room in the Kiel building. Miss Agnes Denison was the first librarian. In March, 1937, the library was turned over to the township to maintain. The La Porte County Public Library is now responsible for the operation of the Hanna Branch Library.Today Hanna has a estimated population of 400 to 500 people. Hanna has three churches and a volunteer fire department. Also located in Hanna are Midwest Argri, Inc., Hooper Products, Hanna Post Office, Hanna Family Medical Center, Hanna Branch Library and several small businesses.