The official enumeration date for the 1890 census was June 1, 1890.   Enumerators were to prepare separate schedules for each family, even distributing them early, with expanded questions to gather information not in previous census records.
This was the first census that was tabulated by machine.  Herman Hollerith had invented the machine which allowed census information to be entered on machine readable medium.  This new technology reduced the tabulation time for the census from eight years for 1880 to one year for the 1890 census.
Most of the 1890 census records were destroyed by fire in 1921 which occurred in the basement of the Commercial Building in Washington, D.C.  Twenty-five percent of the records were destroyed by the fire and another fifty percent received smoke and water damage.
The 1890 census data "reported that the distribution of the population had resulted in the disappearance of the American frontier."  "The US Census Bureau would no longer track the westward migration of the U.S. population."