From their site: GovTrack.us tracks the U.S. Congress and is a reference for legislation, votes, Members of Congress, congressional districts, and the congressional record. The database that powers the site is also made freely available, and several APIs are available. APIs are URLs on GovTrack that serve XML rather than HTML. They are intended to be called by applications to retrieve data dynamically.
The following is a list of historical changes that were made to this asset. Typically, once an API is published on ProgrammableWeb.com, the data we keep about that asset gets updated over the course of its life. For example, the endpoint or home page of the documentation might change. As a means of enforcing the integrity of our data, every time a non-trivial change is made to the data we keep about an asset, we require the entry of some changelog text before that change can be saved. This way, we have a great audit trail of all activity surrounding the asset. For each asset, the changelogs begins with the moment an asset is approved for publication on ProgrammableWeb. If you spot an error in our data and believe that a record needs to be updated in some way, the ProgrammableWeb team would very much like to hear from you at email@example.com
18-06-15 12:02:07[SDK] GovTrack.us Node.js Library by Mark Guerra updated with Related API GovTrack.us
24-11-14 15:24:49[SDK] GovTrack Node.js Library govtrack-node updated with Related API GovTrack.us
25-04-14 02:04:07[Mashup] SOPA and PIPA Standings updated with Related API GovTrack.us
25-04-14 01:57:32[Mashup] Bill's In The News updated with Related API GovTrack.us
25-04-14 01:41:27[Mashup] Influence Tracker updated with Related API GovTrack.us