Hajj unites Muslims because it brings them together to perform an act of worship towards God (Allah). They all perform Hajj to obey Allah and seek forgiveness. Hajj is also performed at a specific time (i.e in the lunar month of Thul-Hijjah) so a lot of Muslims congregate to do this mandatory act of worship.
It would be "the Environmental Protection Agency" that primarily deals with domestic policy issues, since this agency protects the environment of the United States.
