Long distance hiking

Thru-Hiking:

Maps: America's Best Long Trails From Backpacker

"Thru-hiking is hiking a long-distance trail end-to-end. The term is most commonly associated with the Appalachian Trail (AT), the Pacific Crest Trail(PCT), and the Continental Divide Trail(CDT) in the United States, but also refers to other end-to-end hikes. Other examples include the Te Araroa Trail in New Zealand, the Camino de Santiago in Spain, the Lycian Way in Turkey, the Israel National Trail, and the Great Divide Trail (GDT) in Canada. Thru-hiking is also called "end-to-end hiking" or "end-to-ending" on some trails, like Vermont's Long Trail. Section hiking, on the other hand, refers to hiking a trail one section at a time, without continuity and not necessarily in sequence with the other sections." From Wikipedia the free encyclopedia

I found that Wikipedia has information on Long Distance Trails in the United States 
State Wildlife Trails Wikipedia (click on state to see a list of State Trails)
Wikipedia also has information on Long Distance Footpaths.
Here is a link to Great Long-distance Walks of the World
Traildino the World's largest hiking trail database

Info on Long Distance trails:
East Coast Greenway Trail A 3000 mile hike and bike trail from Canada to Key West. A new alternative to the Appalachian Trail. This is a PDF guide to the trail
The Empire State Trail a 750 mile route to be completed in 2020. This is a link to the routes.
The Cowboy Trail is a 321 mile Rails to Trails trail.
The Abraham Path The place for hospitality, meeting and human encounters
The Pacific Northwest Trail is 1200 miles long. Starts at Glacier National Park and goes to the Pacific Ocean
Trans Canada Trail and other multi-use trails More than 17,000 KM in length when completed.
Trans Canada Trail Foundation

Long Distance Blogs, Websites and Articles (not found on Walk-Hike info Tab)

Articles:
Backpacker Magazine Article: 8 Dreamy Trails That Aren't the Triple Crown by Emelie Frojen
How to Thru-Hike the 133-Mile Northville-Placid Trail Marmot for Life 11/11/16
Solo Hiking: The Gifts of Going Alone by Tami Ankeny 8/16/16 Outdoor Project
The Beginner Backpacker Backpacking and Hiking Guide for Beginners
The New Wisdom 6 Long-Trail Legends Share Hard Won Advice Hiking Project Journal

Blogs, journals, personal websites:
Anish Hikes Anish has hiked nearly 30,000 miles since 2003 to include a double triple crown
Barney Scout Mann Author/Hiker/Outdoor Advocate
Following the PCT: Dorothy's (Bacon Bit) Thru-Hike Journal
Guthook Hikes! Hike Light, Hike Far, Hike Often
Hiking Dude "Hiking is just walking with an attitude"
Hiking Tamara Moots Designs
Liz 'Snorkel' Thomas- Liz Thomas Hiking
Mary E Davison Through hiker Triple Crown started at age 60 author
Mic Lowther Backpacking America's Back Country Trails
Nourishing Journey about Food and Hiking Anna Herby
The Big Outside by Michael Lanza
The Hiking Life Tips, Tales and Trail Reports
The Life Peripatetic blog
Through Hiker Journals - Backpacking journals and photos from Long Distance Hikers
Walking with Wired Erin "Wired" Saver's Journal including the Triple Crown

Organizational Websites:
ALDHA-West (American Long Distance Hiking Association) Website
Right On Trek Plan your next multi-day backpacking adventure
Section Hiker's - Hiking and Backpacking for Beginner's and Experts

Certifications, Courses, Trainings:

AIM Adventure U Online courses example backpacking, climbing, skiing, climbing etc... (not free)
Base Medical Online Wilderness Medicine
P3 Protect. Preserve. Promote - A new program launched by PCTA, Eagle Creek, LEKI, and Osprey

Post Trail Depression This topic is becoming more mainstream now as more people are doing through hikes or other long distance trails. I sort of see it as having similarities with people who experience war and come back home and have to integrate back into society where the change from the constant reality between life and death is traded with decisions about where to go shopping or scheduling a manicure.
Not to trivialize war but I believe the integration back into living in a structured society is difficult. I wanted to post about this, not to discourage people from having adventures but to create more awareness about this.

Post Trail Life Documentary from Matt Parker on Vimeo.

ADT (American Discovery Trail)

The Story of the American Discovery Trail
American Discovery Trail trail directory

AT (Appalachian Trail)

Appalachian Trail Conservancy - Ensuring the Trail's Future
American Hiking Society The Appalachian Trail Movie
How to Hike the Appalachian Trail (The Definitive Guide) from Backpackerverse.com
How to Thru Hike the Appalachian Trail a 101 Guide
The Appalachian Trail Thru-Hiker Pass Program
The Long Start to the Journey (The Appalachian Trail Movie)
Trail place An Appalachian Trail Resource Website

Filmmaker: ‘Paul’s Boots’ reminds us not to wait to do the things we love
REI Blog about Paul's Boots

CDT (Continental Divide Trail)

The Continental Divide Trail Coalition

GDT (The Great Divide Trail)

The Great Divide Trail Association

(DVD) Walking the Great Divide Movie trailer

JMT (John Muir Trail)

Mile Mile & A Half can be bought on DVD
The Muir Project

PCT (Pacific Crest Trail)

Craig's PCT Planner Welcome to Craig's PCT Planner
Do More With Less A New Documentary about the PCT (PCTA Blog)
Double Tap Hikes Learn how to hike the PCT trail.
Pacific Crest Trail Association - The Pacific Crest Trail Association