What are the visa & residency requirements in Wash DC?

"In order to obtain a visa to live in Washington DC, applicants must first submit an application to the US Citizenship and Immigration Services (USCIS). This application must include proof of identity, proof of financial support, and a valid passport. Once the application is approved, the applicant will receive a visa that allows them to enter the United States. In order to apply for residency in Washington DC, applicants must first submit an application to the DC Department of Human Services. This application must include proof of identity, proof of financial support, and proof of legal status in the United States. Once the application is approved, the applicant will receive a residency card that allows them to live and work in the District of Columbia," mentioned another expat when asked about moving to Wash DC.