FIRST WOMEN The Grace and Power of America's Modern First Ladies By Kate Anderson Brower

In her introduction, the author quotes from a letter written by a lady from Texas to First Lady Betty Ford, "Your are constitutionally required to be perfect." Lady Bird Johnson said a first lady needs to be a "showman and a salesman, a clotheshorse and a publicity sounding board, with a good heart, and a real interest in folks."

Filling a position not set forth in the Constitution (sorry lady from Texas), first ladies, from Martha Washington to Melania Trump, have defined their role for themselves. Some have remained in the background, some have become advocates for a cause and some have had...