U.S. Coin Price Guide

Coin Collecting

Buy Coin Supplies

Sandwich coins started in 1965
By Paul Gilkes

In 1965, the United States Mint began issuing the first of its clad coinage. A clad coin, in the case of the U.S. issues, is one in which outer layers of one metal or alloy are bonded to an inner core of another metal or alloy.

Use of a copper-nickel clad composition in Roosevelt dimes, above, and Washington quarter dollars began in 1965. The Kennedy half dollars of 1965 to 1970 are of a silver-copper clad composition totaling 40 percent silver.

The copper core is visible on the edge of this manganese-brass clad 2007 George Washington Presidential dollar, left, released from the Philadelphia Mint without the mandated edge lettering. The clad composition containing manganese-brass in the outer layers was introduced in 2000 on the Sacagawea dollar, right.

From 1793 to the mid-1960s, virtually all U.S. coinage compositions were either a pure metal (the copper half cents and cents of 1793 to 1857) or homogenous alloys of two or more metals. Only the 1943 Lincoln zinc-coated steel cent broke the mold, being made of a steel composition with a thin outer coating of zinc on the obverse and reverse (but not the edge).

Homogenous compositions, however, would fall victim to rising metals prices and other factors in the mid-20th century, and would lead to significant changes in coinage compositions, starting with the silver coins.

Coinage Act of 1965

From the 1830s to the mid-1960s, with a few exceptions, the composition of silver U.S. coins was a homogenous alloy of 90 percent silver and 10 percent copper.

By the early 1960s, however, silver was beginning to be in short supply even as mintages were rising in response to the needs of commerce among a growing population. The silver used in the composition was being taken from ever-diminishing national stockpiles of the metal, and a worldwide shortage of the metal hindered likelihood of the stockpiles being replaced or replenished. Changing the composition required an act of Congress (the Coinage Act of 1965, signed into law by President Johnson on July 23, 1965) since coinage alloys are designated by law. For the dime and quarter dollar, starting in 1965, the planchet composition was mandated as two outer layers of copper-nickel (each 75 percent copper, 25 percent nickel), bonded to a core of pure copper. In total, the new composition incorporated 91.67 percent copper and 8.33 percent nickel.

According to the Annual Report of the Director of the Mint for fiscal year 1965 ending June 30 of that year, the Coinage Act of 1965 incorporated the culmination of more than two years of research into the use of silver in coinage, and the study of compositional alternatives to the 90 percent silver, 10 percent copper alloyed composition used for about 130 years for the dime, quarter dollar and half dollar.

The legislation that eventually became the Coinage Act of 1965 took into account the findings of two studies, published in two reports: the Treasury Staff Study of Silver and Coinage and Battelle Memorial Institute's A Study of Alloys Suitable for Use as United States Coinage.

The Mint's comprehensive experience in manufacturing domestic and foreign coinages in many different metals and alloys proved invaluable in the extensive research, according to the 1965 Mint director's report.

Nonmetallic materials, including plastics and ceramics, were rejected from consideration based on available technology. Twenty metals were eliminated during a preliminary screening. The remaining 12 metals were examined as a single metal or as an alloying element.

The Treasury and Battelle studies tested homogenous silver alloys ranging in fineness from .200 to .500; nickel-silver (65 percent copper, 18 percent nickel and 17 percent zinc); copper-nickel or cupronickel (75 percent copper, 25 percent nickel); cupronickel clad and nickel-silver clad, on copper; columbium; zirconium; Monel (a trademark of Special Metals Corp. for a series of nickel alloys, primarily composed of up to 67 percent nickel, along with copper, as well as some iron and other trace elements); stainless steels; and a 95 percent nickel, 5 percent silicon alloy containing a magnetic core.

While the existing alloy of 90 percent silver, 10 percent copper, was found to be "unequaled" at the conclusion of the two studies, it was determined that the United States could not continue the large-scale consumption of silver from government stockpiles to produce subsidiary denominations.

According to the findings, the only alternative to meet the criteria was the copper-nickel clad composition. In 1965, production of the Roosevelt dime and the Washington quarter dollar was converted to use the copper-nickel clad composition, and the coins were nicknamed "sandwich" coins because of the composition's three layers.

The copper-nickel clad composition would not be adopted for the Kennedy half dollar for circulation and for annual sets, but rather a silver-copper clad composition (totaling 40 percent silver), per provisions of the Coinage Act of 1965.

Retaining, then dropping silver

Reasoning for retaining some silver as part of the half dollar's composition was in order to maintain a more than 170-year-old tradition of silver coinage (prior to 1837 when the 90 percent silver alloy was adopted for the half dime to dollar, other silver alloys were used).

From 1965 through 1970, Kennedy half dollars struck for circulation or annual sets were produced in a silver-copper clad composition. That composition represents two outer layers of an 80 percent silver and 20 percent copper alloy, bonded to a core of 21.5 percent silver and 78.5 percent copper, for a total composition of 40 percent silver, 60 percent copper. That silver composition would not be used for circulation for long, however.

Public Law 91-607, approved Dec. 31, 1970, authorized the Eisenhower dollar. The act also amended the Coinage Act of 1965 by requiring the half dollar and dollar denominations to be produced from the same copper-nickel clad composition used for the dime and quarter dollar since 1965. Thus silver was eliminated from all newly minted circulating coinage.

Some silver coinage production was retained, though not for circulation. Public Law 91-607 also authorized the production of Eisenhower dollars in the 40 percent silver composition in 1971 for special sets. The Mint would use the same 40 percent silver-copper clad composition for various collector coins in the 1970s. It was used on the dual-dated 1776-1976 Bicentennial quarter dollar, half dollar and dollar in Proof and Uncirculated sets, as well as for Proof and Uncirculated collector versions of the regular-design Eisenhower dollars from 1971 to 1974.

The 1776-1976 Bicentennial quarter dollars, half dollars and dollars struck in 1975 and 1976 for circulation were produced from the now standard copper-nickel clad composition. The same copper-nickel clad composition was employed for the Anthony dollars in 1979, 1980 and 1981, and again in 1999, despite extensive compositional testing conducted a few years before the smaller dollar coin was first released.

New studies

According to the Mint director's annual report for 1976, the Mint's Office of Technology conducted an in-depth investigation for the proposed small dollar coin (what became the Anthony dollar).

The study included a number of different coin sizes and 12 alloy and clad metal compositions. Also studied were long-term availability of coinage metals, and the anti-counterfeiting and vending machine viability properties for the various compositions. The comprehensive report covering the testing, including review by the Treasury Department along with survey data reported by Research Triangle Institute, was issued in August 1976.

The findings included recommendations that were a mixture of change and retention of the status quo. The findings recommended a new dollar coin having a diameter of 26.5 millimeters and weight of 8 grams, replacing the Eisenhower dollar of 38.1 millimeters and 22.68 grams. Rather than recommend one of the new compositions tested, the findings suggested retaining the copper-nickel clad composition.

The authorizing legislation, the Susan B. Anthony Dollar Coin Act of 1978, adopted those parameters.

The Anthony dollar failed to circulate widely, with $1 Federal Reserve notes still being used and the dollar coin confused with the quarter dollar because of its similar size.

As Anthony dollar stocks in the mid-1990s approached levels that would prompt new Federal Reserve orders for new dollar coins, Treasury and Mint officials made it clear that they did not want to issue new Anthony dollars. When legislation was passed in 1997 for what would become the Sacagawea dollar introduced in 2000, officials were looking for a metal composition that would help distinguish the new dollar from other coins already in circulation: the Anthony dollars (however limited its circulation) and the quarter dollar, 5-cent coin and cent.

The United States $1 Coin Act of 1997 (Public Law 105-124, Sec. 4), required a "golden dollar": a coin having a golden color, with the same diameter as the Anthony dollar coin, but a smooth edge (in contrast to the reeded edge of the Anthony dollar), and a wider border than other current U.S. circulating coinage. The gold-colored alloy, the smooth edge and the wider border were features intended to easily distinguish the "Golden Dollar coin" from other coins, for both the sighted and the vision-impaired.

Testing of different alloys was conducted in-house by the Mint technical staff as well as by outside vendors. An alloy was eventually adopted that an outside vendor consulting with the Mint had in its portfolio of coinage alloys and clad compositions. (Meanwhile, unable to develop the replacement coin in time to fill the Federal Reserve's first orders for dollar coins, the Mint had to strike the 1999 Anthony dollars for circulation.)

The chosen composition was manganese-brass clad, the third clad composition to be used by the U.S. Mint (after the copper-nickel and silver-copper clad compositions).

The manganese-brass clad composition is in the two outer layers, each an alloy containing 77 percent copper, 12 percent zinc (thus the brass portion of the alloy's name), 7 percent manganese and 4 percent nickel. The core is pure copper. Taken together, the overall composition of the Sacagawea dollar is 88.5 percent copper, 6 percent zinc, 3.5 percent manganese and 2 percent nickel.

The same composition was retained for the Presidential dollar series introduced in 2007 under provisions of the Presidential $1 Coin Act of 2005. The composition is also slated for use in producing the Native American dollar coin series, set to debut in 2009 under provisions of the Native American $1 Coin Act of 2007.

© 1992-2018 DC2NET™, Inc. All Rights Reserved