The National Archives and Records Administration (NARA) in Washington, DC and its Regional Branches, is the principal repository for records relating to the US federal government. These include the original paper copies of the federal census, all pre-World War I military records, Native American records, military service and pension records, naturalization records, ship passenger lists, land-entry case files, and homestead and bounty land warrant records. NARA's website is the place to begin research for federal records.
Know your relationships: An ancestor is a person from whom you are descended. A descendant is a person who is descended from an ancestor. A relative is someone with whom you share a common ancestor but who is not in your direct line.
When the head of the household is no longer listed, don't assume he/she is dead. It's possible that the former head of household is now living with one of the children.
The 1900 and 1910 censuses lists the number of children that were born to each woman and how many were still living at the time of the census.
Information Primary: The information in this source contains details provided by someone with firsthand knowledge of the person, event, or situation. (ie: A Birth Certificate)
[Sources & Evidence]