Voyage from yesteryear

OH NO! HUMANS FROM EARTH! Late in the 21st century nuclear war once again loomed on the horizon. And this time there would be no escape. But an American probe has discovered a second life-bearing planet waiting with open biosphere for refugees from Earth; so that freedom, and the human race itself, shall not perish from the universe, the Americans launch a crash project to colonize Chiron. There's only one problem: the science and engineering of the time are not up to the task of transporting living humans between star systems. The answer: send a "colony" of frozen sperm and ova, and use robots to quicken them at the other end. Then use humanlike robots to raise the resulting children. Amazingly, it works. The children and their children's children are happy, healthy, and steeped in the ideals of America's Founders. They are everything their home-planet sponsors could have hoped for except that they really mean it about all that liberty stuff. But now the Earthmen have had their war, survived, rebuilt and come to Chiron in new fast ships. They're the government. They've come to help. But the damned Colonials have such an attitude.