In 1964, there was a severe shortage of coins.
 Silver prices were rising, and the public responded by hoarding not only the wildly popular new coin, the Kennedy half dollar, but the other denominations, including the non-silver cent and nickel.
 Hopeful that issuing more 1964-dated coins would counter the speculation in them, the Treasury obtained Congressional authorization to continue striking 1964-dated coins into 1965.

The Mint's production of coins rapidly depleted the Treasury's stock of silver.
 Prices for the metal were rising to such an extent that, by early June 1965, a dollar in silver coin contained 93.3 cents' worth of it at market prices.
 On June 3, 1965, President Lyndon Johnson announced plans to eliminate silver from the dime and quarter in favor of a clad composition, with layers of copper-nickel on each side of a layer of pure copper.
 The half dollar was changed from 90% silver to 40%.
 Congress passed the Coinage Act of 1965 in July, under which the Mint transitioned from striking 1964-dated silver quarters to striking 1965-dated clad quarters.
 Beginning on August 1, 1966, the Mint began to strike 1966-dated pieces, and thereafter it resumed the normal practice of striking the current year's date on each piece.

The new clad quarters were struck without mint mark in 1965–1967, regardless of the mint of origin.
 Beginning in 1968, mint marks were used again, except that Philadelphia continued to issue coins without them.
 The San Francisco Mint had reopened, but from 1968, it struck quarters only for collectors, for the most part proof coins.
 The Mint adjusted both sides of the coin for the initiation of clad coinage, lowering the relief (the modified reverse design exists on some 1964-dated silver quarters).
 The obverse was slightly changed in 1974, with some details sharpened.
 Mint marks on post-1967 pieces are found on the lower right of the obverse, to the right of Washington's neck.

In January 1973, Representative Richard C. White introduced legislation for commemorative dollars and half dollars for the 1976 United States Bicentennial.
 On June 6, Mint Director Mary Brooks testified before a congressional committee, and responding to concerns that only the two least-popular denominations would be changed, agreed to support the temporary redesign of the quarter as well.
On October 18, 1973, President Richard Nixon signed legislation mandating a temporary redesign of the three denominations for all coins issued after July 4, 1975, and struck before January 1, 1977.
 These pieces would bear the double date 1776–1976.
 In addition to circulation pieces, Congress mandated that 45 million Bicentennial coins be struck in 40% silver.
 Fearful of creating low-mintage pieces which might be hoarded as the cent recently had been, thus creating a shortage of quarters, in December 1974 the Mint obtained congressional approval to continue striking 1974-dated quarters, half dollars and dollars until Bicentennial coinage began.
 Accordingly, there are no 1975-dated quarters.
Almost two billion Bicentennial quarters were struck, as the Mint sought to assure that there would be plenty of souvenirs of the anniversary.
 The Mint sold the silver sets, in both uncirculated and proof, for more than a decade before ending sales at the end of 1986.
 Jack L. Ahr's colonial drummer, which had appeared on the Bicentennial quarter, was replaced after 1976 by Flanagan's original reverse.

Beginning in 1976, and continuing over the following twenty years, Mint engravers modified the design a number of times.
 Quarters were struck at the West Point Mint between 1977 and 1979, but they bore no mint mark.
The Philadelphia Mint's mint mark "P" was used on coins struck at that facility beginning in 1980.
 Coins dated 1982 and 1983, both from Philadelphia and Denver, command a large premium over face value when found in near-pristine condition.
 Beginning in 1992, the Mint began selling silver proof sets, including a quarter struck in .900 silver; this has continued to the present day.
 Although President George H.W. Bush signed
In 1964, there was a severe shortage of coins.  Silver prices were rising, and the public responded by hoarding not only the wildly popular new coin, the Kennedy half dollar, but the other denominations, including the non-silver cent and nickel.  Hopeful that issuing more 1964-dated coins would counter the speculation in them, the Treasury obtained Congressional authorization to continue striking 1964-dated coins into 1965.
The Mint's production of coins rapidly depleted the Treasury's stock of silver.  Prices for the metal were rising to such an extent that, by early June 1965, a dollar in silver coin contained 93.3 cents' worth of it at market prices.  On June 3, 1965, President Lyndon Johnson announced plans to eliminate silver from the dime and quarter in favor of a clad composition, with layers of copper-nickel on each side of a layer of pure copper.  The half dollar was changed from 90% silver to 40%.  Congress passed the Coinage Act of 1965 in July, under which the Mint transitioned from striking 1964-dated silver quarters to striking 1965-dated clad quarters.  Beginning on August 1, 1966, the Mint began to strike 1966-dated pieces, and thereafter it resumed the normal practice of striking the current year's date on each piece.
The new clad quarters were struck without mint mark in 1965–1967, regardless of the mint of origin.  Beginning in 1968, mint marks were used again, except that Philadelphia continued to issue coins without them.  The San Francisco Mint had reopened, but from 1968, it struck quarters only for collectors, for the most part proof coins.  The Mint adjusted both sides of the coin for the initiation of clad coinage, lowering the relief (the modified reverse design exists on some 1964-dated silver quarters).  The obverse was slightly changed in 1974, with some details sharpened.  Mint marks on post-1967 pieces are found on the lower right of the obverse, to the right of Washington's neck.
In January 1973, Representative Richard C. White introduced legislation for commemorative dollars and half dollars for the 1976 United States Bicentennial.  On June 6, Mint Director Mary Brooks testified before a congressional committee, and responding to concerns that only the two least-popular denominations would be changed, agreed to support the temporary redesign of the quarter as well. On October 18, 1973, President Richard Nixon signed legislation mandating a temporary redesign of the three denominations for all coins issued after July 4, 1975, and struck before January 1, 1977.  These pieces would bear the double date 1776–1976.  In addition to circulation pieces, Congress mandated that 45 million Bicentennial coins be struck in 40% silver.  Fearful of creating low-mintage pieces which might be hoarded as the cent recently had been, thus creating a shortage of quarters, in December 1974 the Mint obtained congressional approval to continue striking 1974-dated quarters, half dollars and dollars until Bicentennial coinage began.  Accordingly, there are no 1975-dated quarters. Almost two billion Bicentennial quarters were struck, as the Mint sought to assure that there would be plenty of souvenirs of the anniversary.  The Mint sold the silver sets, in both uncirculated and proof, for more than a decade before ending sales at the end of 1986.  Jack L. Ahr's colonial drummer, which had appeared on the Bicentennial quarter, was replaced after 1976 by Flanagan's original reverse.
Beginning in 1976, and continuing over the following twenty years, Mint engravers modified the design a number of times.  Quarters were struck at the West Point Mint between 1977 and 1979, but they bore no mint mark. The Philadelphia Mint's mint mark "P" was used on coins struck at that facility beginning in 1980.  Coins dated 1982 and 1983, both from Philadelphia and Denver, command a large premium over face value when found in near-pristine condition.  Beginning in 1992, the Mint began selling silver proof sets, including a quarter struck in .900 silver; this has continued to the present day.  Although President George H.W. Bush signed 
Washington quarter