While Castleblayney and Carrickmacross have benefitted from being on the major road from Dublin to Derry, both Clones and Ballybay have suffered economic decline from the Victorian age of industrial competition. Clones has experienced more recent economic problems with its proximity to the border after 1921, losing its natural hinterland in Co. Fermanagh, and since 1957 with the closure of The Great Northern Railway which had served the town.

In the 20th century Monaghan has developed as a modern agricultural economy, based on small farms, services and small industries. In spite of border problems and relative isolation, the county has been successful through enterprise and its towns are now the subject of dynamic urban renewal. Castleblayney is mostly concentrated along a wide main street which leads directly past the 19th Century Courthouse and Library into the former Blayney and Hope families' demesne. Hope Castle is a 19th century house next to a spectacular lake. The demesne with its house, lake and grounds make up Lough Muckno Leisure Park which has provided a new lease of life for this historic site which was occupied by landlord families from earlier times.

The Blayneys were in occupation (in a previously existing building) from the 17th century to the 19th, followed by the Hopes. In this century, Hope Castle was, in turn, a temporary hospital and a convent. It now provides public recreation facilities and catering services.

Eoin O'Duffy (1889-1944) was a native of Lough Egish near Castleblayney. He was one of the most important figures in 20th Century Irish history. He was the Irish Garda (Police) Commissioner (1922-1933) and led the 'Blueshirt' movement in the 1930s after he left the Garda�.

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