New Inn developed at the convergence of two tracks, the Roman road running South to North (Sarn Helen) and an important track, (later a drove road) from West to East. By the mid 19th Century it had become the commercial centre for the area, having three public houses besides the important Travellers Rest, a hostelry. Almost opposite was located the general store owned and operated by the Rees family. From here vast quantities of butter and some cheese were sent to Carmarthen Docks to be shipped out of the County, mainly to Bristol.
The arrival of the railway in Pencader acted as a magnet for commercial activity and in the space of a few years trade started to decline in New Inn.
New Inn now comprises of some sixty dwellings together with a school, chapel, agricultural machinery merchant, two engineering companies and a tour operator.