why adopt internationally when there are kids in America who need families?

Why do missions in other countries when there are those in America who haven't heard the Gospel yet? 

That's the comparison I make when this question comes up. Thankfully there are many (though many are still needed) who adopt kids from the U.S. - both through domestic infant or private adoptions and also out of the foster system. We have dear friends who have done both. For us, adopting internationally and specifically from China was a matter of calling. In missions, we aren't called to just go to the country in which we live, but Acts 1:8 tells us, "you will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth." In missions we are called to go to the ends of the earth to tell of the good news of the Gospel of Jesus Christ. In the same way, when God calls us to look after orphans and widows in their distress (James 1:27), he doesn't put any qualifiers on it - he doesn't tell us to only go to the orphans in the area/country in which we live. Just as there are those who are sent out as missionaries to plant churches in America and to lead RUF to reach the lost on college campuses, so there are those who are called to adopt and foster the needy and orphaned in America. Just as there are those who are sent out to other countries to preach the word of God - to Prague, to India, to the Middle East, to Africa, so there are those who are called to adopt those vulnerable and orphaned children in the world beyond America. What's sad is that international adoptions by U.S. citizens has been declining. In 2004, there were an estimated 23,000 international adoptions by U.S. citizens. Fast forward to fiscal year 2014, and there were only 6,441 children adopted internationally (data from the US State Department). There's an interesting CNN article here on the reasons for the decline in international adoptions. The decline is not due to a decreasing number of orphans worldwide (I wish), but instead due to rising regulations (some with good intentions - for child protection, but often with not enough workers in place to meet the rising demands of the regulations) and political forces in sending countries. Ultimately, we feel that God has called us to China, we feel that He has a girl for us there. We are all made uniquely and given unique gifts, abilities, and callings, for which I am so glad - because what a boring place the world would be if we humans were all the same. Adam and I are so thankful to be unified in this calling. Though there are many daunting barriers ahead (especially the cost, estimated close to ~$40K, more on that later), we know that God is able and he is faithful.