Source: Board of Governors of the Federal Reserve System (US)  

Release: H.4.1 Factors Affecting Reserve Balances  

Units:  Billions of U.S. Dollars, Not Seasonally Adjusted

Frequency:  Weekly, Ending Wednesday

Currency in circulation includes paper currency and coin held both by the public and in the vaults of depository institutions. The total includes Treasury estimates of coins outstanding and Treasury paper currency outstanding. This definition of currency in circulation differs from the currency component of the money stock, a measure of currency used in some other Federal Reserve reports (for example, the H.6 release), which excludes currency held in vaults of depository institutions.

1984-1985 and Jan 11-Mar 15, 1989: Annual Statistical Digest 1984, 1985, 1989 Table 2.
Jan 8, 1986 to date except weeks ending Jan 11, 1989 - Mar 15, 1989: Federal Reserve Board H.4.1.

Source: Board of Governors of the Federal Reserve System (US)  

Release: H.4.1 Factors Affecting Reserve Balances  

Units:  Billions of Dollars, Not Seasonally Adjusted

Frequency:  Weekly, Ending Wednesday

Feb 1984 - Dec 1990: Annual Statistical Digest, various issues, Table 2.
Jan 1991 to date: Federal Reserve Board, H.4.1.
Service-related deposits are the sum of "required clearing balances" and "adjustments to compensate for float." For more details, see http://www.federalreserve.gov/releases/h41/20120719/

Source: Board of Governors of the Federal Reserve System (US)  

Release: H.4.1 Factors Affecting Reserve Balances  

Units:  Billions of U.S. Dollars, Not Seasonally Adjusted

Frequency:  Weekly, Ending Wednesday

Feb 1984 - Dec 1990: Annual Statistical Digest, various issues, Table 2.
Jan 1991 to date: Federal Reserve Board, H.4.1.
Reserve balances with Federal Reserve Banks are the difference between "total factors supplying reserve funds" and "total factors, other than reserve balances, absorbing reserve funds." This item includes balances at the Federal Reserve of all depository institutions that are used to satisfy reserve requirements and balances held in excess of balance requirements. It excludes reserves held in the form of cash in bank vaults, and excludes service-related deposits

Source: Federal Reserve Bank of St. Louis  

Release: St. Louis Weekly Reserves and Monetary Base  

Units:  Billions of Dollars, Not Seasonally Adjusted

Frequency:  Weekly, Ending Wednesday

Updates of this series will be ceased on December 19, 2019. Interested users can construct a proxy by summing Currency in circulation (H.4.1 release); Service Related Balances and Adjustments (H.4.1 release); and Reserve Balances with FR Banks (H.4.1 release). The discontinued series plotted on the same graph with the calculated data can be accessed for comparison here.
For more details, see the FRED Announcement.