Jansen was born on 21 March 1852 in Berdiansk, a port city on the northern coast of the Sea of Azov in the Russian Empire where his family had a grain exporting business.
When the government began withdrawing special privileges granted to colonists such as freedom from conscription, Jansen's father advised concerned Mennonites to emigrate to North America.
Quaker contacts brought them to Washington, D.C., where Jansen had a chance meeting with George Armstrong Custer along with a delegation of "stoic aboriginies"[3] and was introduced to President Grant[4]: 94 who was interested in encouraging immigration of Mennonites from Russia.
Jansen purchased 1280 acres (5 km2) eighteen miles west of Beatrice where he begin building a merino sheep flock.
[4]: 95 Jansen enlarged the ranch by purchasing nearby property, erecting and improving barns and homes for workers and planting trees for shelter and fruit.
In 1886 the Chicago, Rock Island and Pacific Railroad surveyed for a new line running west from Saint Joseph, Missouri near Jansen's property.