In 1792, the U.S. Mint experimented with silver center cents. Two blanks are on display at the Philadelphia Mint.
Tales From the Vault: The 1792 Half Disme - American Numismatic Association : American Numismatic Association
Rare Pennies Expected To Fetch $1M In SoCal Auction - CBS San Francisco
1792 Quarter Dollar, Judd-13, Pollock-15, High R.7 AU58 NGC., Lot #4960
1 Cent 1792 Silver Center and Copper (Pattern) - United States – Numista
File:1792 Silver center cent pattern, obverse.jpg - Wikipedia
Newman Numismatic Portal at Washington University in St. Louis
United States Pattern Coinage of 1792
1792 Silver Center Cent 2 Coin Tribute Set, The Patrick Mint, Silver & Copper BU
National Museum of American History
Washington – Getz Patterns – 1792 - APMEX