The GAA in North America became the victim of two major developments in the early 21st century . One was the security clampdown that followed the 9/11 terrorist attacks , and the other was the massive growth in the Irish ' Celtic Tiger ' economy . These two factors led to a reduction in the number of people travelling from Ireland to the U.S. , and it became difficult for many Irish people to stay in the country illegally . Additionally , many Irish emigrants returned to Ireland , where they enjoyed a high standard of living that was n't available to earlier generations . These factors reduced the number of people playing GAA in larger U.S. cities . The trend was partially offset by growth in smaller cities . With the onset of economic crisis of the late 2000s the flow of emigrants back to Ireland and into America has changed once again but current U.S. immigration policies have meant that the number of Irish that used to go to America is not now the same
9/11 terrorist attacks
September 11 attacks
United States GAA