A prosperous, black-educated class had developed in traditional professions such as social work, ministry, medicine, and nursing. Many other blacks working outside manufacturing were relegated to service industries as waiters, porters, or janitors. Many black women were limited to work in domestic service. Certain business sectors were known to discriminate against hiring blacks, even at entry-level positions. It took picketing by Arthur Johnson and the Detroit chapter of the NAACP before First Federal Bank hired their first black tellers and clerks. Housing in Detroit had been a major problem due to the industrial boom that started in the early 20th century. Several urban renewal projects after World War II, intended to improve housing, dramatically changed neighborhood boundaries and ethnic composition. Affordability for industrial workers and the sheer number of new people in the city resulted in a housing shortage, ultimately fostering the need to establish federal loan systems and invest in public housing, especially for minority populations. Detroit undertook a series of urban renewal projects that disproportionately affected blacks, who occupied some of the oldest housing. Racial discrimination in housing was federally enforced by redlining and restrictive covenants in the mid 20th century. They played an important role in segregating Detroit and escalating racial tensions in the city. The Home Owners' Loan Corporation was in charge of assigning ratings of "A" (green) through "D" (red) to all of the neighborhoods in major U.S. cities based on the conditions of the buildings, the infrastructure and most importantly, the racial composition of the area. Residents of a neighborhood with a "C" or "D" rating struggled to get loans, and almost all neighborhoods with any African American population were rated "D", effectively segregating the city by race. This effectively limited options for African Americans to purchase houses outside of these areas, or acquire resources to repair their already damaged homes in these areas. In fact, only 0.8% of all new construction in the city was available to African Americans Black Bottom and Paradise Valley located on Detroit's lower east side, south of Gratiot, were examples of African-American neighborhoods that formed as a result of these government restrictions. Examples of city projects for housing include the massive Gratiot Redevelopment Project, planned as early as 1946. It was planned eventually to cover a site on the lower east side that included Hastings Street — the center of Paradise Valley. Other public housing projects also resulted in more tension between whites and blacks in the city. Although it seemed positive for working class individuals, the negative effects can still be felt today.