Green Township was organized on July 9, 1824, containing about 27 square miles. Early settlers were Ephraim Jones, Samuel Jones, Abraham Jones, John Knight, William Knight, Stephen Knight, Andrew Sprowls, Isaac Mitchell, senior, Baldwin Cox, John Dunn, Zadcock West, Barnet Adamson, John Bowie, William Hurd, John Reed, Edward Reed, Isaac Cowley, William Hickman, James Seals, Conrad Duval, William Bailey, Jacob Dennis, Henry Dennis, Bennett Coen, Frederick Myers, Adam Myers, and David Honnell.
It is claimed that Ephraim Jones built the first log cabin around 1815 on Crane's Nest Fork, a mile Northeast of where the Town of New Castle is now located.
The first child born in Green Township was Nancy Hurd, daughter of William Hurd and Mary Hurd. John Henderson was the first person to be married in Green Township although his wife's maiden name is unknown. The first election was held about one-half mile West of where New Castle is now located on the land of Isaac Mitchell.
The first grist mill was a horse power mill which was built around 1823 by Baldwin Cox. Around 1834, William Ullom built a saw mill on Crane's Nest Fork. A subscription school was taught by Jacob Miller in 1825. A writer concerning this school wrote the following: "The terms of subscription were one dollar per scholar for a term of three months. The teacher, boarded round among the scholars, that is, he boarded in the families of the scholars, free, for the length of time warranted by the number of pupils sent to school by or from each family." Before the holy days, the teacher was compelled to sign an article that on Christmas or New Year's Day he would treat the scholars to gingercakes and apples or they would bar him out of the school house, or, if he got in first, they would smoke him out. If he still refused to sign the article, they would take him to the nearest creek, and duck him.
The first postoffice was located at the house of Randolph Laing, Southeast of New Castle, and it was called Laings. Later it was moved to New Castle.
The first sermon was preached by Reverend John Secrist in 1821 at the house of Conrad Duval. The first society was organized around 1826 at what is known as the Ott M.E. Church. The Presbyterian church was the second church organized in Green Township. Reverend Alex McCandlas was among the first ministers.
Newcastle was organized around 1836 by Frederick and William Myers.