What were the Soviets and Americans racing to develop in the 1950s?

As the Cold War intensified, both the Soviet Union and the United States embarked upon efforts to rapidly develop and grow their respective nuclear arsenals. Shortly after the US launched its hydrogen bomb program in the early 1950s, the USSR followed suit and initiated their own hydrogen bomb program .

Explanation:

the answer is a glaciers carved a large valley that later flooded and became puget sound

by 1880, germany had more rail lines than great britain and russia.