The official title is actually, "An Act to execute certain treaty stipulations relating to Chinese." That sounds a lot better than the Chinese Exclusion Act, doesn't it? We're sort of lucky someone had managed to slap it with that more direct and honest moniker.

The "treaty stipulations" the act refers to are those in the Angell Treaty negotiated in 1880 by diplomat James Angell. That new treaty was to update the old Burlingame Treaty, which the Chinese Exclusion Act, as it was later written, would ignore.

The Angell Treaty allowed the United States to limit Chinese immigration, and so they did, with the Chinese Exclusion Act. It's likely the government of China didn't know how much the U.S. would limit immigration. Chester A. Arthur kind of went whole hog with the law there.