AP Photo

As the 1960s dawned, few Americans had ever seen a baby elephant. It had been more than 40 years since an elephant had been born in North America, and then only at a circus — never in a zoo.

But in a ramshackle exhibit yard at Seattle's Woodland Park Zoo, in the summer of 1960, the extraordinary occurred: A 15,000-pound male, Thonglaw, mated with a much smaller female, Belle, and Belle became pregnant.