Where did Irish immigrants settle in America?

Lots of places. About twelve percent of Americans claim Irish ancestory. Massachusetts and New Hampshire are the two states who's largest ethnic population is Irish and Norfolk County which is directly under and to the south west of Boston (Suffolk County) in Massachusetts has the largest Irish population of any county in the US. Perhaps the two cities where major Irish imigration was occuring in the 18th and 19th century were Boston and New York. The majority of laborers on the Erie Canal were Irish. Other major populations included Philadelphia, Chicago, and Baltimore. Basically any city that provided cheap manual labor saw huge increases in Irish immigration because of the state of Ireland at the time.