A millwright by trade, John was an ordained Baptist minister in 1797 and an evangelist at Cornish in 1798. He preached in Cornish, Lebanon, Buxton, Limington, Bethel, Harrison, and Dixmont ME. He was pastor of the Baptist Church at N Limington 1799-1802, a missionary in Etna and Carmel and vicinity 1807 to 1808, pastor at Dixmont 1809-1811, supplied them occasionally 1816-1826, and became their pastor again in 1827 until his death in 1831. In Sanford he was known as Elder John Chadbourne, First (to distinguish him from the other John). He was of Cornish in the 1790 census with 1 male over 16, 3 males under 16, and 5 females. His first six children were born in Sanford, three in Cornish, and the last one in Bethel (TR). In Bethel he lived at the lower part of town. He was one of the founders of Dixmont and, with his sons, built the first grist-mill and made their own mill-stones in 1807 on Folsome Brook. He was in the 1810 census of Dixmont with 3 boys and 4 girls and in 1820 with 2 boys and 1 girl, so it seems one married son or daughter was still with him.