1890s American boy

Were he old enough to have been breeched for he’d outgrown his short white dresses, he’d wear blouses with rounded or pointed collars and knickers (knee points, nickerbockers) and stockings or knee socks. If it were a dress suit, it would likely be accompanied by a machine-made lace collar, probably to his great chagrin. Other styles were ruffled or Eton collars with or without bows. Sailor suits were also popular, and some ruffled collars were detachable and fashioned in sailor suit style. Costuming can rely on yokes and epaulettes, as well. He would likely wear a jacket or might sport a cape. Boys usually wore hats including boater hats. Caps were coming into fashion, as well. Perhaps a flat cap that later gained popularity with newsboys would be worn. Footwear would be laceup boots, although shoes were gaining favor for dressy occasions.

Accessories that were commonplace would be canes and cigarettes, for legislation banning the sale of tobacco to minors was ineffectual, by and large. He might also have a rifle at hand, a ball, or a beverage in a long, stoppered bottle. Though the practice of modern orthodontics was still in its infancy, some appliances were in use. So you might have a boy don headgear.