International adoptions of children from other countries, to the United States have collapsed:

From: International adoptions have dropped 72 percent since 2005 – here’s why (theconversation.com)
The last remaining large source has been China – which announced yesterday it will be banning international adoptions: China ends international adoption. Reactions range from shock to relief | WUSF
The reasons for the collapse of international adoptions include:
- Demographic changes – there are low fertility rates, and hence, far, fewer children, in much of the world
- Costs – costs of an international adoption are said to have risen a lot
- Policy changes, including concerns over cross cultural adoptions