You did not give birth dates or where they lived in the US, but I found one family from Sedlec Bohemia, who departed Hamburg 24 Mar 1876 on the ship Pommerania and arrived at the port of New York on 7 Jun 1876. The family consisted of Peter Kucera 26, Elisabeth 22, Wenzel 2, and Joseph 2months.
Dear Ms. Witt,
Thank you for posting your request on History Hub!
We suggest that you review these Genealogy: Passenger Arrival List Research Tips to learn how to locate immigration information for Peter Kucera. There are numerous ways that individuals could enter the United States from Europe such as via a ship to a larger number of coastal ports or over land from Canada, etc. Ship passenger arrival lists were a requirement beginning in 1820, but that does not guarantee that person was recorded or that the list still exists. Many of the passenger lists have been digitized and are name-searchable online at Ancestry.com and FamilySearch.org. There may be a fee for using Ancestry. Instead, you may wish to contact your local library. Many library systems subscribe to these sites, making them free for patrons.
If you have an idea of where the vessel may have departed from Europe, it would be useful to look at passenger departure lists. Therefore, we suggest that you check the immigration data available on NARA’s Access to Archival Databases List of Series - Genealogy/ Personal History: Passenger Lists.
We also suggest that you review the FamilySearch research wiki on Czech Republic Emigration and Immigration.
We hope this is helpful. Best of luck with your research!
[Information provided by Elizabeth Burnes, Subject Matter Expert]