In 1955, at 18 years of age, Senior married a girl called Kezia from the local village. It was Kezia who remained his one true love and to whom he always returned.
She was a 16-year-old schoolgirl while Senior, two years older, had just got his first proper job as an office clerk in Nairobi.
Kezia said: "It was at a dance in Kendu Bay, my home town. Barack (Senior) was there on holiday with his family.
"I went to the dance hall with my cousin William and I saw Barack enter the room. I thought, 'ohhh, wow'. He was so lovely with his dancing. So handsome and so smart.
"We danced together and then the next day my cousin came to our house and told me that Barack liked me.
Obama committed bigamy when he married Stanley Anna Dunham, Democratic candidate Barack Obama's mother in 1960.
"It was December, so I was off school. Each day Barack and my cousin would stop by the house.
"Every time I looked they were always there, trying to convince me to go with Barack to Nairobi.
"About a week later, William and I took Barack to the station. We were going to say: 'Bye bye, see you next time.' Except there was no bye bye.
"When the train arrived William and Barack said, "You are going to Nairobi." I went with him.'
Her father, a local driver, was furious.
Kezia said: "He did not like Obama. My father and brothers came to Nairobi to bring me back. They said I had to go back to school.
"When I wouldn't, they said they would never speak to me again.
"Barack was also worried about what his father (grandfather) would think because I was so young, but he gave us his approval. He sent my mother and father 14 cows for my dowry.
Kezia and Barack Sr. set up home in Jericho, a section of Nairobi created for government employees, and began a family.
First son Roy was born in March 1958. Kezia insisted: "Barack was a good husband."
Although still married to Kezia in 1960, Senior marries fellow student Anna Dunham. Senior is now legally a bigamist. Over his lifetime and through several wives, Senior eventually returns to Kezia.
His own father and motherís wedding in Hawaii may not have been properly documented. "How and when the marriage occurred remains a bit murky, a bill of particulars that I have never quite had the courage to explore," Obama writes in his memoir.
Obama weighed eight pounds, two ounces when he was born on August 4, 1961 (p. 22 of Dreams from My Father), so we can assume he went close to full term, or nine months.
His parentsí marriage took place six months before his birth on February 2nd, 1961. Nine months before Obamaís birth would be early November 1960, about three to four weeks before Ann Dunhamís 18th birthday on November 29, 1960.
It appears that Barack Sr., a married man of about 24, almost certainly impregnated a 17-year-old Dunham.
The Dunhams weren't happy with the union, but Barack Senior's father was furious. He wrote the Dunhams "this long, nasty letter saying that he didn't approve of the marriage," Obama recounted his mother telling him in "Dreams." "He didn't want the Obama blood sullied by a white woman."