Question: Who founded the political party associated with Sinn Féin Bank?

Context paragraphs:
Sinn Féin (newspaper): Sinn Féin was a weekly Irish nationalist newspaper edited by the Dublin typesetter, journalist and political thinker Arthur Griffith.  It was published by the Sinn Féin Printing & Publishing Company Ltd. (SFPP) between 1906 and 1914, and replaced an earlier newspaper called the "United Irishman" which was liquidated after a libel suit.  The SFPP brought out the "Sinn Féin Daily" in 1909 but had to abandon it when it plunged the company into enormous debt.  The "Sinn Féin" weekly and the SFPP both came to an end when they were suppressed by the British Government in 1914.

Leader of Sinn Féin: The leader of Sinn Féin (alternatively known as the "Uachtarán Shinn Féin" or "President of Sinn Féin") is the most senior politician within the Sinn Féin political party in Ireland.  Since 13 November 1983, the office has been held by Gerry Adams, following the resignation of Ruairí Ó Brádaigh as leader of the party.

Sinn Féin (slogan): Sinn Féin ("ourselves" or "we ourselves") and Sinn Féin Amháin ("ourselves only / ourselves alone / solely us") are Irish-language phrases used as a political slogan by Irish nationalists in the late nineteenth and early twentieth century.  While advocating Irish national self-reliance, its precise political meaning was undefined, variously interpreted as the aim of a separate Irish republic or (as advocated by Arthur Griffith) that of a dual monarchy.  Its earliest use was to describe individual political radicals unconnected with any party and espousing a more "advanced nationalism" than the Irish Home Rule movement.  In the 1890s "Sinn Féin, Sinn Féin amháin" was the slogan of the Gaelic League, which advocated the revival of the Irish language.

Sinn Féin Bank: The Sinn Féin Bank, formally the Sinn Féin Co-operative People's Bank, Ltd. (Irish: "Coṁar-Ḃannc Sinn Féin, Teo." )  was a co-operative bank in Ireland associated with the Sinn Féin movement, which operated from August 1908 to October 1921.  The Sinn Féin Bank is sometimes confused with the National Land Bank, established as a friendly society in 1919 with Dáil backing and premises at 5 Harcourt Street.

Republican Sinn Féin: Republican Sinn Féin or RSF (Irish: "Sinn Féin Poblachtach" ) is an Irish republican political party in Ireland.  RSF claims to be heirs of the Sinn Féin party founded in 1905 and took its present form in 1986 following a split in Sinn Féin.  RSF members take seats when elected to local Irish councils but do not recognise the validity of the partition of Ireland and subsequently the legitimacy of the Northern Ireland (Stormont) or Republic of Ireland (Leinster House) parliaments, so the party does not register itself with them.

Sinn Féin Republican Youth: Sinn Féin Republican Youth (known as Ógra Shinn Féin until 2012) (Irish: "Sinn Féin Óige Phoblachtach" ) is the youth wing of the Irish political party Sinn Féin.  SFRY is active and organised throughout Ireland and the United Kingdom.

Sinn Féin Funds case: The Sinn Féin Funds case ("Buckley and Others v. the Attorney-General and Another") was a 1942–48 Irish court case in which the Sinn Féin party claimed ownership of funds deposited with the High Court in 1924 which had belonged to the Sinn Féin party before 1923.  The Sinn Féin Funds Act 1947, which attempted to halt the court case and assign the funds to Bord Cistí Sinn Féin, was ruled unconstitutional by the Supreme Court in an important judgement on separation of powers and private property rights.  The original action was subsequently decided against Sinn Féin, on the basis that the pre-1923 party was separate from the 1940s party.  Most of the disputed funds were consumed by legal costs.

Workers' Party of Ireland: The Workers' Party (Irish: "Páirtí na nOibrithe" ), originally known as Official Sinn Féin, is a Marxist–Leninist political party active throughout Ireland.  The party originated with a split between factions of Sinn Féin (which was founded in 1905) and the Irish Republican Army (IRA), which took place in 1969–70, early in the Troubles.  The faction that broke away became known as the Provisional Irish Republican Army and Provisional Sinn Féin.  The Officials' leaders at the time the Provisionals left were Cathal Goulding and Tomás Mac Giolla.

History of Sinn Féin: Sinn Féin (""We Ourselves"", often mistranslated as "Ourselves Alone") is the name of an Irish political party founded in 1905 by Arthur Griffith.  It subsequently became a focus for various forms of Irish nationalism, especially Irish republicanism.  Its splits during the Irish Civil War in 1922 and again at the beginning of the Troubles in 1969 had dramatic effects on politics in Ireland.  Sinn Féin today is a republican, left-wing and secular party.

Samuel O'Flaherty: Samuel O'Flaherty (died 22 May 1930) was an Irish Sinn Féin politician.  He first stood for election at the 1918 general election as a Sinn Féin candidate for the Donegal East constituency but was defeated by Edward Kelly of the Irish Parliamentary Party.  He was elected unopposed as a Sinn Féin Teachta Dála (TD) to the 2nd Dáil at the 1921 elections for the Donegal constituency.  He opposed the Anglo-Irish Treaty and voted against it.  He was re-elected unopposed as an anti-Treaty Sinn Féin TD at the 1922 general election but did not take his seat.  He lost his seat at the 1923 general election.

Supporting paragraphs: Sinn Féin Bank History of Sinn Féin
Answer: Arthur Griffith