Genealogy is the study and tracing of family lineages and history. Genealogical research is a complex process that uses historical records to establish biological, genetic, or familial kinship. Reliable conclusions are based on the quality of sources, ideally original records, the information within those sources, ideally primary or firsthand information, and the evidence that can be drawn, directly or indirectly, from that information. In many instances, genealogists must skillfully assemble indirect or circumstantial evidence to build a case for identity and kinship. All evidence and conclusions, together with the documentation that supports them, is then assembled to create a cohesive "genealogy" or "family history." Traditionalists may differentiate between these last two terms, using the former to describe skeletal accounts of kinship (aka family trees) and the latter as a "fleshing out" of lives and personal histories. However, historical, social, and family context is in any case essential to achieving correct identification of individuals and relationships.
The Roosevelt family is a prominent American political family of Dutch origin that produced two United States Presidents, Theodore Roosevelt and Franklin D. Roosevelt, and a First Lady, Eleanor Roosevelt. The first member of the Roosevelt family in America was Claes van Rosevelt (or Rosenvelt), who arrived in New York (then known as Nieuw Amsterdam) around 1649, possibly as early as 1638. It has been suggested that Claes may have been related to the van Rosevelt family that lived in Oud-Vossemeer in Zeeland province of the Netherlands at that time, but no definite link has been established. Around 1652, Claes Martensen van Rosenvelt bought a farm comprising twenty-four morgens in what is now Midtown Manhattan, including the present site of the Empire State Building.
In the eighteenth century the Roosevelt family divided into two branches, the Hyde Park Roosevelts, who by the late 19th century were Democrats, and the Oyster Bay Roosevelts, who generally became Republicans. President Theodore Roosevelt, an Oyster Bay Republican, was President Franklin Roosevelt's fifth cousin. Despite their political differences, which led family members to actively campaign against each other, the two branches generally remained friendly: James Roosevelt met his wife at a Roosevelt family gathering in the home of Theodore's mother, and James' son Franklin married Theodore's niece Eleanor.