What route does a letter take from AZ to NJ?

When a letter is sent from Arizona (AZ) to New Jersey (NJ), it first goes to a local post office where it's sorted. From there, it is transported to a regional processing center, where it undergoes further sorting based on its destination. After sorting, the letter is sent via air or ground transportation to the appropriate regional center in New Jersey, where it is sorted again before being delivered to the local post office for final delivery to the recipient. This entire process typically takes a few days, depending on the service chosen.