Some personal secrets are so well-kept that even family and friends are oblivious. So it is with the story of the late Chief Justice William Rehnquist's marriage proposal to a Stanford Law School classmate in the early 1950s. When 19-year-old Sandra Day entered Stanford Law School in 1949, her frequent seatmate was 26-year-old Bill Rehnquist, attending Stanford on the GI Bill. The two shared their equally meticulous class notes and eventually were dating regularly. But by December of their second year, she broke up with him while somehow retaining what she called their "study buddy" relationship; she even entered the...