PLEASE HELP! Close Reading: Lines 24 - 27 read: "You couldn't be American if you were blind or going to be blind. That much she understood." What does this tell you about the medical examination from the perspective of arriving immigrants?

The government wanted to keep the number of free and slave states equal so that neither of would throw off the balance of congress.
For example, if there was more slave states in congress, then most likely the laws would be made in favor of slavery. Or vice versa. 
Hope this helps! Have a happy holiday!