I see you are new to posting on a Rootsweb message board (at least under this user name). When you post, it is important to provide the persons birth date if you have it. Other information you have is also important to volunteers to see exactly what you already know. It "appears" that your posting of 1900 and 1910 indicates you already had the census information for those years; but, I'll add to the potential misconceptions as posted by the other. Information in the US Census is NOT always accurate, it depends on the knowledge of the person providing the information and the accuracy of the enumerator. In many cases, the enumerator did not speak the foreign language and could not understand the English spoken. If you know Anna's maiden name, research on her could help fill in some blanks. "Perhaps" they met in South Dakota and moved to Nebraska...as a scenario for the below. Any information you can identify helps bonifide researchers an avenue for research. The records "indicate" they immigrated separately and may not have known each other in the Fatherland.
The 1900 Census for Hoskins shows the immigration year for Anna as Unknown, not 1890. Henry and Anna were married for seven years at the time of enumeration of the census, 14 June; so, they could have been married in 1892 or 1893.
The 1910 Census for Hoskins shows Henry as being what appears to be in his first marriage (m 1) of 16 years. The Census was enumerated on the 27th of April, so marriage could have been in 1893/1894. Henry was born in Russia/German Speaking, to Russia born/German speaking father and a German born/German Speaking mother. His Immigration was in 1893/naturalization status was "Pa" meaning he had filed his Declaration of Intent to become a citizen (First papers).
Mary, 43, shown as being in her first marriage of 16 years, born in Nebraska to father born in Russia/German speaking and mother born in Nebraska. While this indicates Mary was not Anna in the 1900 census, there are MANY such errors in the Census. So, proof would be needed either way.
The 1920 Census of Hanson, Ransom COunty, North Dakota
Henry, age 50(1869/1870), immigrated 1892/Pa (Papers)
Mary, age 54 (1865/1866), immigrated 1894/Al (Alien). In 1920, the wife's citizenship was the same as her husbands. Even a US Born female became an Alien, if her husband was an Alien. This changed in 1922 when Congress passed the Married Womans Act, giving a woman her own citizenship status.
--Both are shown as born in Russia/German Speaking, with both parents born in Russia/German Speaking. This would probably indicate that the information on Mary in the 1910 Census was in error.
I would "GUESS" that Henry and Mary were part of a very large group of Russian Citizens whose parents or grandparents had been born in Germany, but due to religious persecution (Mennonites), they emigrated to Russia. When Russia began persecuting them (military service requirements, etc), they emigrated in mass to the mid-west (Kansas, Minnesota, the Dakota's, Nebraska). While they meet the "criteria" of this, it would have to be proven.
The below is a "potential" person for being Henry Bachman. This person, Heinrich, was born about the same year and immigrated about the same year. I don't know what total information you may have on this person, family knowledge of sibings, documents such as his death certificate, other information in North Dakota "might" connect him.
New York Passenger lists show arrival on July 8, 1890 on the "Fulda."
Friedrich Bachmann, age 58, butcher, (all born in Russia)
Friederike, wife, born about 1837
Heinrich, born about 1868
Katharine, born about 1872
Anton, born about 1875
Friedrich, born about 1879
--The 1900 Census of Township 99, Hutchinson, South Dakota
Fredrich Bachman, bon May 1832 in Russia, immigrated 1890
Fredricky, born Sep 1837, mother of 12/8 living
Anton, born Jan 1875, imm 1890
Fredrick, born Dec 1878, imm 1890.