J. P. Morgan in London and New York before 1914Before 1914, London had a stock exchange that was larger and qualitatively more developed than New York's. Yet the London Stock Exchange has received a bad press from historians, while the New York Exchange has achieved star billing. This forensic reexamination of J. P. Morgan–a player in both markets–suggests that such a historiography is egregiously biased. Morgan's higher profi ts in New York derived partly from insider deals and partly from monopolistic exactions that U.S. protectionism facilitated but that proved more problematic in the U.K.'s open, competitive markets. Morgan's contributions to the impressive catch-up process by the New York Exchange are more plausibly viewed as successful emulation of European securities-market precedents on routine matters than of the allegedly path-breaking “information-signaling” innovations of more Panglossian accounts.