Ivy League is a style of men's dress, popular during the late 1950s in the Northeastern United States, and said to have originated on college campuses, particularly those of the Ivy League. The clothing stores J. Press and Brooks Brothers represented perhaps the quintessential Ivy League dress manner, the former with two of its four locations found at Harvard and Yale Universities (the Princeton branch closed in 1942). The Ivy League style was the predecessor to the preppy style of dress. The Ivy League Style is epitomized by the sack suit which is defined as being a 3-to-2 (3 buttons with the top button "rolled" back to reveal only two usable buttons) blazer without darts and a single "hooked" vent. The pants are typically cuffed and without pleats. It was also characterized by the use of natural fabrics, shirts with button-down collars, and penny loafers. In suits, the Ivy League style was promoted by clothier Brooks Brothers and included natural shoulder single-breasted suit jackets. In 1957 and 1958, about 70% of all suits sold were in the "Ivy League" style.
Controversially, in a recently revised form, a version of this style is sometimes promoted and marketed as "American Trad" or simply "Trad, " although there are marked differences between the two styles. Trad is considerably narrower in scope than the original Ivy League style.
An American style known as preppy is similar to Ivy League but intended for today's mainstream culture. Preppy style tends to be more colorful, especially in spring and summer. It was first popularized in the late 1970s as a return to Ivy League styles after a decade of more modern trends, but today, preppy differs from historic Ivy League. Preppy fashion is influenced by traditional collegiate trends, rather than reproducing them exactly, and various clothing items can be considered preppy based on how they are worn or accented. Today Polo Ralph Lauren, Vineyard Vines, and J. Crew are large marketers of preppy clothing, though each offers a wide range of styles. In recent years, J. Press has taken a modernized approach to the Ivy League Style to accommodate continuing fashion trends. This, however, is also not the original Ivy League style, which was a fashion trend of the 1950s.