to find it you got to go back

至少得回溯到
at least to the 1830s and probably the 1820s.

19世纪30年代很可能是20年代
You can begin to measure this.

可以测算一下
GNP in the United States -- which I guess we call GDP now,

美国的GNP 现在我们叫GDP了
don't we, is that right?

是吧
It used to be GNP; is it GDP now?

以前用GNP 现在用GDP了吧
Gross domestic product --

国内生产总值
was about 1.62 billion in 1840,

1840年大约为16.2亿
it was about 2.4 billion in 1850,

1850年是大约24亿
and on the eve of the Civil War in 1860 it was about 4.1 billion.

内战开始前的1860年大约为41亿
So GDP had more than tripled

所以GDP从1840年到1860年
from 1840 to 1860.

翻了两番多