If your surname is Osterhaus, there is little chance that you are a direct descendant of Peter Joseph. If you know of an Osterhaus ancestor, you may be related through the many female descendants. I didn't include all of their names here but please contact me if you want more information.
Peter Joseph Osterhaus was one of three sons born to Joseph Adolf Oisterhusz and Eleanora Kraemer in Koblenz, Westphalia. One brother, Lorenz, never married. The other, Anton Heinrich, married Katharina Roesgen and had five sons and five daughters, all in Europe.
Although Peter Joseph had many descendants, I believe there are only three living who bear his name: my mother, Elizabeth Osterhaus Bobbitt of Portland, Oregon, and Helen Osterhaus Rafael and George Osterhaus, both of California.
Peter Joseph Osterhaus married twice, to sisters. His first wife, Sybilla Mathilde Born, from Kreuznach, Germany, died just before the battle of Lookout Mountain in November, 1863, leaving the couple's five surviving young children in St. Louis without a relative while Osterhaus was away at the front. The next summer, he married Emma Amalia Born, Mathilde's younger sister, who had come to take over his household while he was gone. This marriage produced four more children.
Peter Joseph's children with Mathilde were:
Eleanor, born 1848, died as an infant in Mannheim, Baden.
Anna, born in 1849 in either Mannheim or Kreuznach while her father was on the run from the Prussians. She made the long voyage to the United States with her parents at the precarious age of one month. While her father was U. S. Consul to Lyon after the Civil War, she married Karl Hartwig and lived in Tussin, France, where he owned a factory. They had at least two children.
Hugo, born in 1851 in Belleville, IL, was the only one of Peter Joseph's children to remain in the United States his entire life. He entered the U. S. Naval Academy at the tender age of fourteen and had a long and distinguished naval career. He was captain of the USS Connecticut, flagship of Teddy Roosevelt's Great White Fleet that toured the world in 1908. He made rear admiral in 1910 and was appointed Commander in Chief of the U. S. Atlantic Fleet the next year, retiring in 1913. He was called out of retirement during World War I to command the U.S. Naval Districts, receiving the Navy Cross for his actions during the war. During World War II a destroyer escort was named for him.
Hugo married Mary Willoughby Wilson from an old Norfolk, Virginia family. (Her father, Confederate George Riddick Wilson, had received a presidential pardon from Andrew Johnson in 1865.) Hugo and Mary had two sons. The oldest, Hugo Wilson Osterhaus, also became a rear admiral in the navy and married Helen Huntington Downing of New York. They had one son, Capt. Hugo Wilson Osterhaus, Jr., who had one daughter, Helen Osterhaus Rafael.
Hugo and Mary's younger son Karl was a physician in the Veteran's Administration most of his career. He married Elizabeth Currie of Nova Scotia and had three daughters, one of whom is Elizabeth Osterhaus Bobbitt.
Adolphus (Otto) was born in Lebanon, IL, in 1852 and died as an infant.
Alexander was born in Lebanon in 1855. After living in Europe and partnering with his dad in a business in Mannheim, he moved with his German-born wife Maria Stebinger to Redondo Beach, CA, where he worked for the public transit company. The couple had three daughters and a son, Hans. Hans had two sons; one is George Osterhaus. Neither son had children of their own.
Emma was born in Lebanon, IL, in 1857. She married Otto Kamp, PhD, who taught high school in Frankfurt. Later living in Bonn, they had five daughters.
Karl was born in Lebanon in 1859 so was still a youngster when his family moved back to Europe after the Civil War. He became a career officer in the German army, ending as a major commanding a battery. He received the Order of the Red Eagle for his actions in China during the Boxer Rebellion and died in German Southwest Africa (now Namibia) of septicemia from wounds received in the Herrero uprising in 1904. He never married.
The mother of all these children, Emma Mathilda, died at age 38 and is buried at Bellefontaine Cemetery in St. Louis.
With her sister Amalie, Peter Joseph had four more children:
Teresa ("Thesy") was born in St. Louis in 1865 during the final days of the war. She married Emil Buth, a paper manufacturer in Julich, Germany. During WWI, Buth, a former Prussian cavalry officer, was military commander of occupied Luxembourg. Thesy, a singer, became a Red Cross leader who ran a hospital caring for wounded of all armies. They had one son.
Ludwig (Louis), one of a pair of twin boys, was born in Kreuznach in 1866 at his grandparents' home while Peter and Amalie were en route to Lyon, France where Peter was to begin an eleven-year stint as U. S. Consul there. Around 1904, Ludwig, a lawyer, returned to live in the U. S., settling in Belleville IL and marrying Josepha Andel, daughter of one of his dad's old war cronies. He practiced in Belleville until his death of gangrene after minor foot surgery. He and Josepha were childless.
Josef, the other twin, died in his twenties in Johannesburg, South Africa. He may also have been an officer in the German army. He married Maria Aller and had one daughter, Mathilde, a pediatric nurse married to pediatrician Hans Roscher.
Mathilde Nathalie was born in Lyon in 1869, moving with her family to Mannheim when she was about eight. She ultimately married Hermann Petersen, a physician and medical school professor who directed the Bonn Polyclinic. They had three daughters, one of whom, Thesi, was a concert singer, and two sons who died in World War II, according to a relative.