Obsolete currency in the United States refers to banknotes and coins that are no longer in circulation and have been withdrawn from use as legal tender. These obsolete forms of currency were issued by various private banks, states, municipalities, and other entities before the establishment of a national currency system in the mid-19th century. Here are some key points about obsolete currency in the United States:

1. Pre-National Currency Era: Before the Civil War, the United States did not have a uniform national currency system. Instead, various banks and other institutions issued their own banknotes and coins, often backed by specie (gold or silver). These banknotes were widely used for everyday transactions, but their value and reliability varied widely depending on the issuing institution.

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3. State Banknotes: Many state-chartered banks issued their own banknotes, which circulated as currency within their respective states. These banknotes typically featured intricate designs and were denominated in dollars or other units of currency.

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5. Obsolete Banknotes: As the national economy expanded and evolved, many of these state-chartered banks failed or went out of business, leaving their banknotes worthless. Other banknotes became obsolete when the federal government established a national currency system with the passage of the National Banking Act of 1863 and the subsequent issuance of national banknotes by federally chartered banks.

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7. Obsolete Coins: In addition to banknotes, various types of coins circulated as currency in the United States before the establishment of a national coinage system. These included foreign coins, colonial coins, and tokens issued by merchants and other private entities. Many of these coins were withdrawn from circulation when the federal government began minting its own coins in the late 18th and early 19th centuries.

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9. Collectibility: Despite being obsolete as legal tender, obsolete currency and coins from the pre-national currency era are highly collectible today. Numismatists and collectors prize these items for their historical significance, artistic merit, and rarity. Some obsolete banknotes and coins can command significant prices on the collector's market, particularly those in good condition or with unique designs.

Overall, obsolete currency in the United States provides a fascinating glimpse into the nation's economic history and the evolution of its currency system. While no longer used for everyday transactions, these artifacts continue to hold value as collectible items and historical artifacts.