It depends what you are basing his birthday on. You can't base it on what you see in the census. They might not be right. In some regions a young man had to be a certain age before he could be hired out to work. In some states it might be ten. You might want to put your son to work or he wants to go to work to help feed the family. So he might lie to go to work. He then would definately lie on the census. Sometimes it follows you right into the Army.
They were registering certain ages at certain dates in WW1 and when it first started out. You had to be twenty one and that meant your birth year fell at a cetrtain time.
They had three registrations at your Local Draft Board and one Supplement. You had to register at a certain time according to your birthay and this included men 31-45 and they had to have been born between September 13, 187 and Sept 12, 1887. If you did not fit into that category because of your birthday then you might lie about the year you were born.
I might mention the three registrations and one supplement between the second and third registrations were as follows.
(1.) First Registration Date: June 5, 1917 Men Eligible: Born between June 6, 1886 and June 5, 1896 (ages 21-31)
(2.) Second Registration Date: June 5, 1918 Men Eligible: Born between June 6, 1896 and June 5, 1897 (Turned 21 since June 5, 1917)
Supplement to 2nd Registration Date: August 24,1918 Men Eligible: All men born between June 6, 1897 and August 24, 1897 (Turned 21 since June 5,1917)
(3.) Third Registration Datye: September 12, 1918 Men Eligible: Born between August 25, 18 and September 12, 1900, or between September 13, 1872 and September 12, 1887
(ages 18-21 or 31-45)
It depended solely on your birthdy and age. So to fall in a certain category. You might lie about your age as to according to when you were born.
You can tell from the Draft card what registration he fell under. Each registration had a different type Draft Card.
The gentlemen was right about registration. Even today you register at a certain age. It does not mean you are going to be drafted; but of course today it is an all volentary Army. It is the law now and it was the law when WW1 broke out.
Just because you register. Doesn't mean you are fit for Duty. At one time you could not be a pilot if your vision was not 20/20. I don't know if it is still the same today.
They use to say the Army would take a one legged man. That's how hard up at one time. Of course i am only joking about the one leg. I really shouldn't joke. There were a lot of good men who went away with two and came back with one and in some cases none. My father left with two and due to the war he wound up with one of his feet being amputated; but he never complained and thought it was apart of his duty or should i say all in the line of duty.