County Tyrone had five Stormont MPs between 1929 and 1972. Mid Tyrone and West Tyrone were strongly nationalist, while the constituencies covering the north and south of the county were consistently won by unionists. East Tyrone was marginal between the two traditions, with nationalists just outnumbering unionists.
Nationalists consistently won the seat, with majorities around 1,000. In the 1958 election, however, the sitting Nationalist MP, Joseph Francis Stewart, was run close by the area's Westminster MP George Forrest (Ulster Unionist MP for Mid Ulster 1956-1969).