I have been hearing and reading that there are celebrations of it being the 100th year since WWI and so I thought I would study about it.
I have heard about a local celebration where they are gathering names of all who served here in Cape Girardeau County during WWI and are going to commemorate them at the Jackson Homecoming parade, along with a publication of their stories. I found Cape Girardeau County WWI Military Service website page and am delighted to see it is online. This page indicates which died in the war and which have biographies available at the archive center. There is a WWI Memorial at the Cape Girardeau County Courthouse in Jackson, Missouri, honoring those who died.
I have heard of free access to records somewhere, for those doing genealogy, but now cannot find who.
World War I began July, 28 1914, and ended with an armistice at the eleventh hour of the eleventh day of the eleventh month in 1918. (November 11, 1918). Therefore, the centenary celebration has been going on for a period of years and does not end until next year. However, the significance of honoring the centenary in 2017 is that the United States entered the war by declaring it on 4 April 1917. (history channel link)
World War I was also known as the First World War, the Great War, or the War to End All Wars.
I want to go through my own genealogy trees and locate anyone who served in WWI. I am assuming the best way to begin this is to look at my tree to see who was living between 1914 and 1918, making a list, and noting their age in 1917. Looking at the draft registration notes below, people between ages 21 and 31 would have been born between 1886 and 1896. For the second draft, it would add the date of 1897. For the third draft with people between ages 18 and 45, people would have been born between the dates of 1873 - 1900.
Here are some research helps. I will edit this post and add more as I find the time.
National Archives | Archives WWI
NPRC, St. Louis
Cyndi's List WWI
Ancestry Military Records | American Soldiers
Military Indexes Links
Family Search | Ancestry
U.S. had 3 draft registrations and the cards can be searched here. Signing up for the draft does not mean they were actually drafted. The first draft was June 5, 1917 for men between 21 and 31 years old. The second draft was June 5, 1918 for men who had reached age 21 since the first draft registration. The third draft registration was on September 12, 1918 for men between the ages of 18 and 45.
Look at the 1930 census (if an ancestor lived that long) which inquires "yes or no" for "whether a veteran of the U.S. military or naval forces mobilized for any war or expedition? The next inquiry is "what war or expedition." This is also a place to find answers for Civil War veterans.