Between 1956 and 1962, the IRA conducted a border campaign against the outposts of the British Army and the Royal Ulster Constabulary with the aim of ending British rule in Northern Ireland. This coincided with a brief electoral success for Sinn Féin, who won four seats in the 1957 Irish parliamentary elections. This is the first electoral success since 1927 and did not win seats in the Republic of Ireland until 1997. The border campaign was totally unsuccessful in its objectives. In 1957, Prime Minister Harold Macmillan wrote: “I don`t think a One Ireland – with Valera as a kind of Irish Nehru – would do us much good. We`re with our friends.  The agreement incorporated provisions that formed part of the Northern Ireland Act 1998 on the form of a future referendum on a united Ireland. In September, Joe Biden , who is re-establishing his roots in County Mayo and County Louth, just on the border that still divides Ireland into two parts – took an inser into the politics of his home country. “We cannot allow the Good Friday agreement, which brought peace to Northern Ireland, to become a victim of Brexit,” he tweeted, referring to the pact that ended three decades of violence on the island. “Any trade agreement between the United States and the United Kingdom must depend on compliance with the agreement and preventing the return of a hard border.” The seemingly endless baroque negotiations to wrest Britain from the European Union have often threatened to reintroduce new barriers between Northern Ireland (part of the United Kingdom) and the Republic of Ireland (an EU member) and Boris Johnson`s government had just announced that it would break a withdrawal agreement it had reached last year with the European Union. In response, the next president of the United States directly threatened something that the UK desperately needs – good relations with Washington – if they actually left. The Irish Convention, which took place between 1917 and 1918, sought to reach agreement on how to implement the post-war regime. All Irish parties were invited, but Sinn Féin boycotted the procedure. At the end of the First World War, a number of moderate trade unionists came to support Home Rule because they believed it was the only way to keep Ireland united in the United Kingdom.
The Irish Dominion League rejected the division of Ireland into separate southern and northern jurisdictions and argued that all of Ireland should be granted dominion status with the British Empire.  In a survey conducted by TheJournal.ie on TDs on support for a border investigation and a unified Ireland in December 2016, only the TDs of the Anti-Independence Alliance (now Solidarity) stated that they were currently opposed to a united Ireland.  The two main political parties in the agreement were the Ulster Unionist Party (UUP), led by David Trimble, and the Social Democratic and Labour Party (SDLP), led by John Hume. The two heads of state and government together won the Nobel Peace Prize in 1998. The other parties to the agreement were Sinn Féin, the Alliance Party and the Progressive Unionist Party. The Democratic Unionist Party (DUP), which later became the largest Unionist party, did not support the agreement. When Sinn Féin and loyalist parties entered, they left the talks because republican and loyalist paramilitary weapons had not been decommissioned.