There has been no quota on immigration into the United States enacted into law for many decades. No major laws were fixed in 1995 which set either an upper or lower limit on immigration. There is currently no immigration quota by country, but there is a cap on immigration.
There have been at least four significant laws which effected a quota, or lack of one, on immigration into the United States:
The Emergency Quota Act of 1921. After World War 1, there were significant problems arising from un- or under-employment and immigration as a result of industrialization, the economic and physical devastation in Europe, and the United States emerging relatively unscathed. The EQA set limits on immigration in order to preserve the ethnic proportions of the United States at their ratios in 1910. The quota effected was that immigrants from any country were limited to 3% of the people from that country who were already living in the United States according to the 1910 census. This reduced immigration by over 50% within one year.
The Immigration Act of 1924. This was largely a revision of the EQA, with the quota limit dropping from 3% to 2%, and total immigration being limited to 150,000. These quotas had a disproportional impact on anyone not of Northern European heritage, substantially limiting these populations from gaining any significant presence in the United States.
The Immigration and Nationality Act of 1965. This was a reversal of previous policies, ostensibly removing the quota system but nevertheless preserving it in a less stringent form. Total immigration was raised to 500,000, and several work programs were significantly affected, drastically affecting the proportion of total immigrants that were illegally entering the country.
The Immigration Act of 1990. This removed all quota systems and replaced them with a tier of needs-based preferences. Total immigration was capped at 675,000.