How are conscription conducted in World War 1 era?

Probably by mail.
“Today’s your lucky day!”

The draft board sends you a letter and you have to show up at the recruiting office.

Somewhere, in some box in the garage, I have my Draft Registration letter from the government, and also my Draft Card. But that’s from 50+ years ago.

Vietnam @elbanditoroso?

@Dutchess_III yes. Although I had to get a draft card, my birth year was the last year of the draft lottery, and my draft lottery number was way up in the 300s. So I was lucky to turn 18 just as the draft (and the war) was winding down.

Whew @elbanditoroso….

Under the office of the Provost Marshal General the Selective Service System was made up of 52 states (or territories) and 4,648 local boards. These organizations were responsible for registering men, classifying them, taking into consideration needs for manpower in certain industries and in agriculture, as well as certain special family situations of the registrants; handling any appeals of these classifications; determining the medical fitness of individual registrants; determining the order in which registrants would be called; calling registrants; and placing them on trains to training centers.

District boards were established by the President (one or more for each Federal Judical District). The average district board had jurisdiction over approximately 30 local boards, each with an average registration of 5,000 men. The district boards had appellate jurisdiction over the decision of local boards in some claims and original jurisdiction in others.

Local boards were established for each county or similar subdivision in each state, and for each 30,000 persons (approximately) in each city or county with a population over 30,000. The local boards were charged with the registration, determination of order and serial numbers, classification, call and entrainment of draftees.

During World War I there were three registrations. The first, on June 5, 1917, was for all men between the ages of 21 and 31. The second, on June 5, 1918, registered those who attained age 21 after June 5, 1917. (A supplemental registration was held on August 24, 1918, for those becoming 21 years old after June 5, 1918. This was included in the second registration.) The third registration was held on September 12, 1918, for men age 18 through 45.

More WWI info and source

When I turned 18 (1966) I was required to report to the local draft board office to register. I don’t remember the exact process, but I was granted a deferment to finish high school. It was pretty well understood that one would be drafted into the Army or the Marines, resulting in an almost sure tickets to the front line in Vietnam.
I was too poor to go to college, and too poor to pay a doctor to diagnose me with “bone spurs” or some other condition to disqualify me.
I eventually enlisted in the Navy to avoid the draft, as so many others did at the time.

@Forever_Free covered it well. I can add a little.

1) Important to know that registration is not induction/drafting into the military. Registration is joining the pool of potential draftees. You may be drafted or not.

2) In the USA, Registration for Selective Service at age 18 has been mandated since 1917 except for a lapse 1975–1980. I registered in the 1980s when I was 18. My 20-something friends are registered.

3) I have copies of my grandfathers’ (plural) WWI-era registration cards. Neither was drafted. They registered and were not selected.