The H-2A nonimmigrant classification applies to an alien seeking to enter the United States to perform agricultural labor or services of a temporary or seasonal nature in the United States.
According to Federal register,
This finalizes interim amendments to the Department of Homeland Security’s (DHS) regulations, published in the Federal Register on February 8, 2016, that eliminated the nonimmigrant visa exemption for certain Caribbean residents seeking to come to the United States as H-2A agricultural workers and the spouses or children who accompany or follow these workers to the United States. As a result of the interim final rule, these nonimmigrants are required to have both a valid passport and visa.
Previously, a visa was not required for H-2A agricultural workers who are British, French, or Netherlands nationals, or nationals of Barbados, Grenada, Jamaica, or Trinidad and Tobago, who have their residence in British, French, or Netherlands territory located in the adjacent islands of the Caribbean area, or in Barbados, Grenada, Jamaica, or Trinidad and Tobago. Additionally, a visa was not required for the spouse or child accompanying or following such an H-2A agricultural worker to the United States.
DHS, in conjunction with DOS, determined that the nonimmigrant visa exemption for these classes of Caribbean residents, when coming to the United States as H-2A agricultural workers or as the spouses or children accompanying or following these workers, was outdated and incongruent with the visa requirement for other H-2A agricultural workers from other countries.
This rule is effective on August 6, 2018.