Cali O'Connor in Seattle, Washington.Courtesy of Cali O'ConnorCali O'Connor bought an Amtrak USA Rail Pass to get from Boston to Napa two summers ago.She spent 96 hours on trains and stopped along the way in three different cities.Though she dealt with noise and slept in a train seat, she said she loved the adventure.This as-told-to essay is based on a conversation with Cali O'Connor, a 35-year-old freelancer from Boston.