Dan Rooney is sworn in as U.S. Ambassador to Ireland by Secretary of State Hillary Clinton

The 27th U.S. Ambassador to Ireland Dan Rooney arrived in the Emerald Isle today to take up his post and move into his residence at Phoenix Park, Dublin.

First up on Rooney’s schedule as ambassador is a presentation of his credentials to Irish President Mary McAleese and a formal celebration of the Fourth of July in Dublin on Friday.

President Barack Obama announced the appointment of long-time Irish supporter as Ambassador on St. Patrick’s Day, and Rooney was officially sworn into the position by Secretary of State Hillary Clinton yesterday.

In a speech at Rooney’s induction ceremony, Clinton praised him, telling the Irish charge d’affaires: “We are sending you one of our very best. There is no greater champion of Irish-American relations than Dan Rooney.”

Ireland has welcomed the appointment of the Irish-American. Taoiseach (Irish Prime Minister) Brian Cowen said: "Dan has been a great personal friend of mine down the years, too, and I really very much welcome his appointment."

Rooney, who traces his roots to Newry, County Down, co-founded the American Ireland Fund, which has raised more than $300 million for programs that support the Northern Ireland peace process. The 76-year-old was recently was honored with the Lifetime Achievement Award by the organization.

A prominent member of the Irish-American community, Rooney is chairman and owner of the highly successful football team the Pittsburgh Steelers, the current NFL champs.

Rooney succeeds the outgoing U.S. Ambassador to Ireland, Thomas Foley, who stepped down from his post on January 20.