When it comes to immigration history, many are familiar with Ellis Island as a point of entry to the United States. But before Ellis Island opened in 1892, hundreds of thousands of immigrants passed through the Port of Galveston, Texas. The vast majority of immigrants arrived through Galveston from the 1840s - 1920s. Immigration records for the Port of Galveston from the latter half of the 19th century through the first half of the 20th century are available online.
In addition, search Library Quick Search: galveston immigration
This finds books and articles on the topic with some focused on immigrants from specific countries.