I want to share this advertisement for a couple of reasons. First, there may be a collector of vintage underthings who has one of these contraptions and will appreciate the identification.

The Wilson Garter for children and pregnant women. It supports the stockings from the shoulders instead of from the waist. LHJ ad, Sept. 1917.
Second, it is just one more example of the way America’s entrance into World War I, in April of 1917, permeated American popular culture.
Wilson Cord and Slide Garters
“Up Like Little Soldiers — That’s how the Cord & Slide Wilson Garter allows children to grow — trim, graceful — all ginger. No more little rounded, stooping shoulders, and no more torn hose tops.
“For Boys and Girls, 1 to 16 years. Shoulder style like picture, slips on over head, white or black, 25 cents. Give Age.
“For Women, same style. Fine for home, athletic or Maternity wear, 50 cents. Bust sizes.”
Digression: I feel I should explain a bit; we live in an era when many people have never worn stockings. (Pantyhose are more popular, if less erotic, than individual thigh-high stockings worn with garter belts.)
When I wore my first garter belt in eighth grade, I was puzzled by ads — like this page from a 1958 Sears catalog — that showed the garters [suspenders] being worn over full petticoats — which would have flattened the petticoat absurdly. I had no mother to ask about this; finally an older girl explained that you actually wore the petticoat on top of the garter belt, but advertisers couldn’t show a garter belt attached to stocking tops over a bare thigh in family magazines.

Garter belts from Sears catalog, Fall 1958. My first garter belt looked like K (bottom center), not P (the black one.) Back then, normal 12 year old girls did not wear black lace undies. However, if you wore stockings when dressed up, you needed a garter belt.
“Pull Up Your Socks!”
It’s hard to conceive of a time when active little children wore stockings instead of socks.
Nevertheless, these little boys are wearing boots with spat-like contrast uppers (or possibly spats! see far right), over stockings probably made of cotton lisle, although wool was a possibility.

A poor boy receives a basket of food from a boy who is better off. Both wear long stockings. Robert A. Graef illustration, Delineator, Nov. 1924.
Because putting on his first pair of “long pants” was once a rite of passage for an adolescent boy, pre-adolescent boys wore knickers or short pants; these left their lower legs exposed all year round — so they sometimes wore long stockings.
Since neither little boys nor little girls have a waist significantly smaller than their hips, keeping trousers, shorts, and stockings from falling down was a problem.
A solution popular in the 1920’s was to button the pants to the shirt, or to a sleeveless underbodice, in front and in back. This made it very difficult for small boys to go to the bathroom without help. (To read “Zippers Are Good for Your Children,” click here. )
Boys didn’t always wear stockings; some wore sensible socks, sometimes rolled over elastic garters, and little boys and girls kept warm by wearing stockings under leggings in the winter. [Like much fashion vocabulary which changes over time, “leggings” now describes a completely different garment, i.e., women’s knit tights that stop at the ankle.] Formerly, stiff (lined) wool or corduroy leggings were buttoned from below the anklebone to above the knee (you needed to use a buttonhook) and must have been a nightmare to put on squirming children.

Clothes for boys, Delineator, Nov. 1917. The smallest boys wear buttoned leggings. Butterick patterns.
Grown men wore long trousers which covered their garters:
Grown women suspended their stockings from their corsets:

La Camille International Corset advertisement, Delineator, April, 1917. Look at those lovely clocked/embroidered stockings! For modesty’s sake, the model is drawn wearing frilly bloomers, which would have made it difficult to attach the suspender to the stocking! Here it is left dangling.
Corsets and stocking suspenders were also worn by some unlucky little girls:
The younger girl’s figure is still unformed, so her corset has shoulder straps to prevent the tension on her stockings from pulling it down. If it only attached to her stocking tops in front, this might produce the “stooped” look mentioned in the Wilson Garter ad.
Like Little Soldiers

Children’s patterns, Butterick’s Delineator, July 1917. The long stockings of the boy on the left are falling down. Note the military insignias on their tunics.
There was a time when a parent, seeking to divert children from mischief, would simply yell, “Pull up your socks!”
However, the pugnacity of these two boys was part of a general trend to illustrate children as little warriors during World War I.

Boy’s Butterick pattern illustration, Delineator, Sept. 1917. A few months earlier, boys were shown flying a kite, not leading a charge “over the top.”

Butterick pattern for boy’s military style outfit, complete with puttees. Delineator, Sept. 1917.
Which brings us back to the Wilson Garter, which “allows children to grow . . . up like little soldiers.” By Jingo.