In 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described Helmdon like this:
HELMDON, a village and a parish in Brackley district, Northampton. The village stands near one of the sources of the river Tove, 4½ miles N of Brackley r. station; is on the line of a new branch of the Northwestern railway; and has a post office under Brackley. The parish comprises 3, 560 acres. Real property, £3,452. Pop., 602. Houses, 53. The property is much subdivided. The manor belongs to Worcester College, Oxford. An excellent building stone, known as Helmdon stone, was long extensively quarried, but is now in only local request
Lace making is considerably carried on. The living is a rectory in the diocese of Peterborough. Value, £267.* Patron, Corpus Christi College, Oxford. The church is decorated English; consists of nave, aisles, and chancel, with a pinnacled tower rebuilt in 1823; and contains a piscina and sedilia. A very large yew tree is in the churchyard. A date on a beam in the parsonage, removed from a previous parsonage, looks to be 1133, but is understood to be 1533, and gave rise to a discussion as to the earliest use of Arabic figures in England. There are a Baptist chapel and a national school.