The OSTP issued a memorandum in 2013 in response to the White House's directive for expanding access to federally funded scientific research. As per the memo, federal agencies with "...more than $100M in R&D expenditures to develop plans to make the published results of federally funded research freely available to the public within one year of publication and requiring researchers to better account for and manage the digital data resulting from federally funded scientific research."
Article and Data Sharing Requirements by Federal Funding Agency
Scholarly Publishing and Academic Resources Coalition (SPARC) maintains "a community resource for tracking, comparing, and understanding both current and future U.S. federal funder requirements for sharing research articles and research data."
Federal funder's response to the OSTP memo (updated as they become available) - University of Minnesota Libraries
Federal Access Mandates - University of Oregon Libraries
Two sources that University of Minnesota Libraries and University of Oregon maintain that provide a comprehensive list of mandates from such agencies.
Crowd sourced spreadsheet of federal agency guidelines in response to OSTP memorandum
Data librarians crowdsourced the creation of this spreadsheet that
Data Management Plan Templates by funding agency
DMPTool maintains a list of DMP templates. These templates are not provided by the funding agencies themselves
US Private Funders
A list of US private funding agencies maintained by Carnegie Mellon University Library
ROARMAP - Repositor of Open Access Repository Mandates and Policies
"The Registry of Open Access Repository Mandates and Policies (ROARMAP) is a searchable international registry charting the growth of open access mandates and policies adopted by universities, research institutions and research funders that require or request their researchers to provide open access to their peer-reviewed research article output by depositing it in an open access repository."