The collapse of the subprime mortgage market in 2008 involved issues of foreclosure, securities sales, bankruptcy, and eminent domain as cities sought to clean up areas affected with blight by excessive numbers of foreclosure. List the sources of law you can see that would be applied in dealing with all of these issues

Foreclosure would require an understanding of state laws, including the provisions on contracts, real property rights, the foreclosure process, and even on interest rates.
Securities sales would be governed by federal law found in the United States Code. There could also be some state securities laws if the mortgage debt instruments sold qualified for an exemption from federal securities laws.

Bankruptcy is an exclusively federal issue - governed by the bankruptcy courts and provisions in the United States Code.

Eminent Domain is a constitutional issue, governed by the Fifth Amendment. There could also be some state constitutional protections. Also, there may be some new states laws on local governments taking property for purposes of economic development.