The First Congress of the United States of America and thus the official commencement of the U.S. federal government under the U.S. Constitution began on March 4, 1789, and ended on March 4, 1791.
This Congress’ First Session (March 4, 1789—September 29, 1989) and Second Session (January 4, 1790—August 12, 1790) took place at Federal Hall in New York City. The Third Session (December 6, 1790—March 3, 1791), at Congress Hall in Philadelphia. Below are drawings of those buildings:
At the start of the First Congress there were 22 senators and 59 representatives. After ratifications of the U.S. Constitution by North Carolina on November 21, 1789, and by Rhode Island on May 29, 1790, there were 26 senators and 64 representatives.
There were no standing committees of this Congress. Instead the Senate and House of Representatives acted as committees of the whole to consider individual bills. Thus, there are no committee reports regarding bills like those that exist today. Moreover, there are no transcripts of debates such as exist today in the Congressional Record. The record of the 94 separate pieces of legislation produced by the First Congress, however, is available in 204 pages of 1 U.S. Statutes.
In addition, the 1st Federal Congress Project at The George Washington University in Washington, D.C. serves as a research/education center for the First Congress and has collected, researched, edited and published the Documentary History of the First Federal Congress, l789-l791 (DHFFC). Fergus Bordewich,the author of The First Congress, acknowledged his indebtedness to this Project, which has “brought together virtually every known piece of writing composed by or about the members of the First Congress . . . as well as the best official records of their debates.” 
As Mr. Bordewich puts it in The First Congress, “Beginning less than two years after the conclusion of the Constitutional Convention and before all thirteen states had ratified that document, the First Congress was charged with creating a new government almost from scratch. No one, neither in Congress nor outside it, knew if it would or could succeed. How it did so is an epic story of political combat, vivid personalities, clashing idealisms, and extraordinary determination. It breathed life into the Constitution, established precedents that still guide the nation’s government, and set the stage for political battles that continue to be fought our across the political landscape of the twenty-first century.” (P. 1)
Subsequent posts will examine the First Congress’ adoption of the first congressional proposed amendments to the U.S. Constitution; the statute creating the federal courts (the Judiciary Act of 1789); the statutes creating the requirements for the first census (An Act providing for the enumeration of the Inhabitants of the United States, 1 Stat. 101 (1790)) and an individual’s becoming a U.S. citizen (the Naturalization Act of 1790); and debates regarding slavery.
 Bordewich, The First Congress: How James Madison, George Washington, and a Group of Extraordinary Men Invented the Government (Simon & Schuster; New York, 2016); 1st United States Congress, Wikipedia; Federal Hall, Wikipedia; Toogood, U.S. Congress (1790-1800), Encyclopedia of Greater Philadelphia; 1 U.S. Stat. 23-225 (1845) (the statutes of the First Congress).
 I have not done any original research regarding the First Congress other than examining the constitutional amendments it proposed and some of the statutes it enacted. Instead for the purpose of this and subsequent posts I have relied on Mr. Bordewich’s book, but I confess that it would be fascinating to examine the records at the 1st Federal Congress Project.