This morning, the U.S. Government Publishing Office released the President's Budget of the United States Government for Fiscal Year 2016. The Goodson Law Library's print copy has not yet arrived, but users can read and search the online version at GPO's FDsys website or through the Office of Management and Budget. An app version for mobile devices reproduces the main budget text, and directs readers to FDsys for access to the supplemental Analytical Perspectives, Appendix, and Historical Tables volumes.
The President's budget request to Congress is step one of the federal appropriations process for the upcoming fiscal year, which for the government begins on October 1. (Although this first step can sometimes be
delayed, today's release meets the traditional due date of the first Monday in February.) Following the President's budget request, Congress then works to pass a budget resolution, which has a target due date of April 15 (but is also frequently delayed). More details about the federal appropriations process can be found on the Center on Budget and Policy Priorities website
and the 2014 Congressional Research Service report The Federal Appropriations Process: An Overview.
Historical budgets can be found through FDsys back to 1996 and through the Federal Reserve or HeinOnline's U.S. Federal Agency Documents, Decisions, and Appeals library back to 1923. The Goodson Law Library also maintains a historical print collection of the federal budget at Documents PrEx 2.8. For assistance with locating current or past federal budgets, be sure to Ask a Librarian.