In 1869, “robber barons” Jay Gould and James Fisk attempted to corner the gold market, enlisting Abel Corbin, Daniel Butterfield, and Tammany Hall. President Grant and Treasury Secretary Boutwell ultimately uncovered the scheme and broke the corner. However, this decision caused a steep drop in the price of gold, triggering a stock market crash that propelled the United States into a months-long financial crisis. Through an examination of the political economy during the volatile transition period between the Reconstruction Era and the Gilded Age, this paper argues that Black Friday served as an early warning of how the unchecked economic power of robber barons can threaten US democracy. Without proper government oversight, operations and corporations led by robber barons can exert undue influence over the administrative process of the state at the expense of the other constituents of society and cause severe damage to the nation’s financial system and economy. First, the paper delves into the factors that enabled Gould and Fisk to corner the market, namely the vulnerable state of the post-Civil War economy and the rampant political corruption of the period. Then, it investigates Gould and Fisk’s plan as well as Grant and Boutwell’s response to the ploy, evaluating the impacts of the administration’s decision to break the corner in light of the economic recession it produced. Finally, it discusses the public’s response and the Congressional investigation of Black Friday, assessing the incident’s role in the decline of the Grant administration’s reputation and the public’s faith in the integrity of American democracy.