What caused the economic panics in the 1800s

basically, it was a financial panic in the United States that was caused by the declining international economy. which caused a "panic", thus getting its name.

The Panic of 1857 was a financial panic in the United States caused by the declining international economy and over-expansion of the domestic economy. Because of the interconnectedness of the world economy by the 1850s, the financial crisis that began in late 1857 was the first worldwide economic crisis.