When were onsies invented?

Onesies, as we know them today, were popularized in the 1980s as a convenient clothing option for infants and toddlers. However, the concept of one-piece garments dates back much further, with similar designs appearing in the early 20th century for children. The term "onesie" itself was trademarked by the Gerber Products Company in the 1980s, which helped establish its widespread use and recognition.