I am booking travel from Seattle through New York JFK (picking up my daughter there, who lives in New York) on to London and Dublin, then back through JFK to Seattle. How much time should I allow in JFK to clear customs and get to my flight to Seattle? LIkely flying Dublin to JFK or London to JFK on British Airways, then traveling Delta airlines from JFK to Sea-Tac airport.
If you fly nonstop from Dublin to JFK then you pre-clear US Immigration and customs in Dublin and just have to claim your bags from Aer Lingus, then re-check them with Delta and go through security. You can do that in 2 hours. If you fly from London I would want at least 3 hours because then you'll have to go through Immigration and Customs in JFK.