The Shropshire Union Canal is a navigable canal in England; the Llangollen and Montgomery canals are the modern names of branches of the SU system and lie mostly in Wales.
The canal lies in Staffordshire, Shropshire and Cheshire in the north-west midlands of England. It links the canal system of the Midlands, centred on Birmingham, with the River Mersey and Manchester Ship Canal at Ellesmere Port, Cheshire.
The "SU main line" runs south east from Ellesmere Port on the River Mersey to the Staffordshire and Worcestershire Canal at Autherley Junction near Wolverhampton. Other links are to the Llangollen Canal (at Hurleston Junction), the Middlewich Branch (at Barbridge Junction), which itself connects with the Trent and Mersey Canal, via the Wardle Canal, and the River Dee (in Chester). With two connections to the Trent and Mersey (via the Middlewich Branch and the Staffordshire and Worcestershire Canal) the SU is part of an important circular and rural holiday route called the Four Counties Ring.
The SU main line was the last trunk narrow canal route to be built in England. It was not completed until 1835 and was the last major civil engineering accomplishment of Thomas Telford.
The name "Shropshire Union" comes from the amalgamation of the various component companies (Ellesmere Canal, Birmingham and Liverpool Junction Canal, Montgomery Canal) that came together to form the Shropshire Union Railways and Canal Company. The main line between Nantwich and Autherley Junction was almost built as a railway although eventually it was decided to construct it as a waterway.
