[sien]

There were 21M horses in the US in 1900. In 1960 there were 3M.

https://history.stackexchange.com/questions/12516/how-common...

[mattzito]

The GP said increased variety, not increased numbers.

[sien]

Yes. However, the magnitude of the decrease is significant and it seemed that it would interest people, as it has, to see the numbers involved in the decline for horses.

For bovines it's likely to be even larger.