“As these photos by LIFE photographers show, there hasn’t exactly been a dress code, though styles have historically erred on the conservative side (in terms of hem lines, not party lines). The first ladies’ fashions have both evolved with popular trends and helped to inspire them. Furs, seen on Eleanor Roosevelt, Bess Truman, Mamie Eisenhower and Lady Bird Johnson, have fallen out of favor in recent decades. Hats, from Truman’s rather vertical design to Kennedy’s pillbox style, are infrequently sported by recent first ladies. Leather, with the exception of Nancy Reagan, shown in 1968 before her First Lady days, has been far from a staple, whereas the simple pearl necklace continues to be a timeless, nonpartisan classic.

While Kennedy’s style was described by LIFE in 1961 as having “an almost deliberate plainness,” Obama does not shy away from a hint of flourish here and there. But she’s certainly not the first to indulge in a bit of flair. When working with a designer on her dress for the inauguration in 1953, Mamie Eisenhower had a few extra requests. “She specified pink and asked for some additional glitter.” Because even the White House—no, especially the White House—can use a little sparkle now and then.”

44 First Lady Fashion Looks from Eleanor Roosevelt to Michelle Obama:
http://time.com/3665827/first-ladies-fashion/