Source: U.S. Bureau of Economic Analysis
Release: U.S. International Transactions
Note that the 1962 Q1 value of 0.000 represents less than +- $500,000.
This series has been discontinued as a result of the comprehensive restructuring of the international economic accounts (http://www.bea.gov/international/modern.htm). For a crosswalk of the old and new series in FRED see: http://research.stlouisfed.org/CompRevisionReleaseID49.xlsx.
U.S. Bureau of Economic Analysis, Foreign Official Assets in the U.S.: Net (DISCONTINUED) [BOPIO], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/BOPIO, May 24, 2017.