The election of Abraham Lincoln in 1860 was the immediate cause of southern resolutions of secession. He was the nominee of the Republican party with an anti-slavery expansion platform, he refused to acknowledge the right to secession, and he would not yield federal property within Southern states.
The gestation period of a human, from time of conception to birth is approximately 9 months (266 days/38 Weeks). 9.5 months is calculated from the first day of the last menstrual period (280 days/40 Weeks).
The time interval of a gestation is called the gestation period. In human obstetrics, gestational age refers to the embryonic or fetal age plus two weeks. This is approximately the duration since the woman's last menstrual period (LMP) began.