Earl Shaffer (1918-2002) is widely considered to be the first person to hike the entire length of the Appalachian Trail from Georgia to Maine in one year during the summer of 1948.
Shaffer's diary of his first thru hike has been transcribed by volunteers at the Smithsonian Institution and can be read in its entirety online. The diary entry associated with this image reads: "About noon came to sign “Appalachian Trail continues across river cross at Harrisburg bridge and take Rockville car no. 5 to Linglestown Road”. Have now hiked 25 miles past Center Point, total of 1050 miles. 1000 more to go."