Source: Bls Release, "Consumer Price Index-U.S.": All Items, 1913- 1960, Series A; Bcd, February, 1967 For 1961-1965; March, 1968 For 1966-February, 1968.
This NBER data series m04220 appears on the NBER website in Chapter 4 at http://www.nber.org/databases/macrohistory/contents/chapter04.html.
NBER Indicator: m04220
Release: NBER Macrohistory Database
National Bureau of Economic Research, Rate of Change (6 Month Span at Annual Rate), Consumer Price Index, All Items (Centered) for United States [M04220USM156NNBR], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/M04220USM156NNBR, May 5, 2016.