The 1978 U.S. Mint 6-Coin Proof Set is a complete collector-assembled presentation featuring all six denominations of U.S. coinage issued for collectors during 1978. Struck at the San Francisco Mint, the set includes the Lincoln Memorial Cent, Jefferson Nickel, Roosevelt Dime, Washington Quarter, Kennedy Half Dollar, and Eisenhower Dollar, each bearing the "S" mintmark. Every coin was specially struck multiple times using highly polished dies and carefully prepared planchets, producing brilliant mirror-like fields, razor-sharp details, and, on many examples, beautiful cameo or deep cameo contrast. While the U.S. Mint officially sold the standard five-coin Proof Set separately from the Eisenhower Proof Dollar, collector-assembled six-coin sets combine all denominations into one attractive display. The 1978-S Eisenhower Dollar, the final coin of the series, was available in both 40% silver and copper-nickel clad versions, so the composition should be identified accordingly. With an official five-coin Proof Set mintage of 3,127,781, the 1978 issue marks the last year the Eisenhower Dollar was produced, before it was replaced by the smaller Susan B. Anthony Dollar in 1979. Complete six-coin sets are especially desirable because they represent the conclusion of the iconic large-size Eisenhower Dollar series while showcasing the exceptional quality and craftsmanship of late-1970s U.S. Proof coinage.