Why did banks refuse to accept paper currency in 1837 leading to the panic of 1837?

In 1837, banks refused to accept paper currency primarily due to a loss of confidence in the financial system, exacerbated by speculative land practices and the overextension of credit. Many banks had issued more paper notes than they could back with gold or silver, leading to fears of insolvency. When the government announced the requirement that land purchases be made in hard currency, it triggered a run on banks, causing widespread failures and ultimately leading to the Panic of 1837. This crisis resulted in severe economic depression and unemployment, as businesses collapsed and credit tightened.