The original Pan Am II flew from Miami to New York on its inaugural route, using an A300-B4, formerly with Eastern, named Clipper Fair Wind. Service to LA from Miami was started later using another former Eastern A300 named Clipper America (different a/c from the original ones that bore these names). Pan Am II was headquartered at Miami.
The airline quickly expanded to destinations like San Juan and Santo Domingo, flying from both New York and Miami with the A300s. Then the company bought out fledgling Carnival Airlines, which had started up about four years previously out of MIA/FLL and offerend low-fare flights that would feed the Carnival Cruise Lines' ships. The company was in bad financial shape, however.
Pan Am's motivation, I think, was to quickly expand their fleet, market share, and destination list very cheaply so that they could become more of a player in the south Florida marketplace. However, buying out a bankrupt carrier (actually, two bankrupt carriers, when you count Chalk's Int'l, which became the Pan Am Air Bridge) is not the best way to remain financially stable. It was deja vu all over again, as Yogi Berra would say, as the National debacle of the early 80s repeated itself in the disguise of Carnival. The combined carrier's service declined, on-time performance worsened, and passengers started staying away. The ValuJet crash outside Miami also hurt the airline, as people became more skeptical of the safety of start-up carriers. By early 1998, Pan Am II was out of business.
The combined Pan Am/Carnival flew at least 8 A300-B4s, 3 737-400s, and 4 727-200s (There were more, I just can't find info on them). Pan Am Air Bridge had three Grumman Mallard seaplanes. You can find a route map, with the combined Pan Am, Carnival, and Pan Am Air Bridge routes here:
Hope that helps.