The phrase that has a connotation of freedom and adventure is: "splashed on through the swamp"
Taking into consideration the context in which that phrase was written we can see in the words "splash" and "swamp" John Muir's perspective of life. He was a naturalist writer who loved traveling and who found freedom and adventure in his experiences in the wild life.
These setting details help establish a mood of a relaxed excitement because the day is beautiful all of the townspeople are present and they seem happy and carefree
