Dunellen may have officially become a town in 1887 but it was already being mentioned in books back in 1882. Below are a few pages from the “Industries of New Jersey: Middlesex, Somerset and Union counties” book by Richards Edwards. It’s available as a downloadable .pdf.
“Like all the villages in this portion of the State, Dunellen is growing gradually in trade and number of inhabitants. The village is located on the Central Railroad of New Jersey, twenty-seven miles from New York city, three west of Plainfield, and four east of Bound Brook. It has twenty-one trains daily, and is rapidly growing in favor as a place of residence for those doing business in the cities to the northeast and who desire a quiet and healthy place for their families. Dunellen combines the advantages of perfect country and city privileges in schools, churches and stores. Population, about 600.”