Before World War II, Mount Pleasant was a bedroom community for Washington's white gentry and civil servants. But during the post-war '50s the neighborhood began to change.

"At that time, it was an integrated area," recalled resident Frank Bloss, who in the 1950s lived in a rooming house in Mount Pleasant. "There were blacks, some Hispanics and poor whites from West Virginia. We had a lot of music in the streets and that kind of stuff . . . "

By 1960, U.S. Census figures began reflecting those changes. According to that census, the neighborhood had 11,554 residents; 8,445 were white, 2,802 were black and 307 were of other races, including 55 Puerto Ricans and 46 Mexicans. The residents were mostly young, married, blue-collar service workers. The median family income was $6,158.

The area had 5,067 housing units, although 223 were vacant. Renters outnumbered homeowners 3,755 to 1,069. Of those who rented homes, 3,424 were white and 351 were black. There were 759 white homeowners and 310 black homeowners.

By 1970, the neighborhood had changed again. Black residents now outnumbered white. Most residents still were young and married, but many worked in white-collar professions. The median family income had risen to $8,090 census, the neighborhood population had dropped to 10,304; the number of black residents had risen to 6,658 and the number of white residents had declined, to 3,332. Included in those figures were 52 Puerto Ricans and 494 other Spanish-speaking people.

The number of housing units had declined to 4,446, including 386 vacant units. There were slightly more homeowners - 802 - than in 1960, but the number of white homeowners had declined significantly to 400, while the number of black homeowners had risen slightly to 364 (38 homeowners were unaccounted for in the statistics). The same pattern was reflected in 3,277 rental units that were occupied in 1970; whites lived in 1,207 rental units and blacks lived in 2,011 (59 renters were unaccounted for).

By 1975, the population had decreased again, to 9,800, according to Municipal Planning Office figures. MPO estimates that the number of housing units in the area has remained fairly stable at the 1970 level of 4,446 units, although the type of occupancy has changed.

For instance, according to the 1970 census, Mount Pleasant had 1,116 single-family homes, 1,019 homes with two to nine units and 2,311 homes with 10 units or more.

Since the fall of 1974, according to Dr. James A. Burns, research director at the D.C. Rental Accommodations Office, 43 families have been evicted or have moved from the neighborhood as the result of changes in 42 homes. Of those 42 homes, 18 were sold, five were renovated and 19 were reclaimed by landlords. Sixty-five families were evicted from the Kenesaw Apartment Building, he said. He added that the figures do not include families that moved after landlords refused to renew leases.

As the composition of the neighborhood has changed, so have the needs and problems of its residents. One group of resident - immigrants from Spanish-speaking countries - have been the focus of several community service programs.

Since 1968, the Spanish Catholic Center at 3055 Mount Pleasant St. NW. has provided job, educational, medical and housing programs that "help immigrants adapt to a new life and country" said center director Father Sean O'Malley.

Volunteer medical staff provides care for a $1 donation. Dental care is provided for the cost of supplies, such as fillings, said Father O'Malley.

A 150-member domestic workers association provides job listings and counseling on minimum wage laws, Social Security, unemployment compensation and other work-related matters, said Silverio Coy, 26, a law student employed by the center.

There are two schools in or near the neighborhood. Last fall, Bancroft Elementary School, at 18th and Newton streets NW, had 526 black youngsters, 17 white children and 51 Hispanos enrolled. At Lincoln Junior High, on 16th Street, there were 825 black students and 14 Hispanis students. No white children were listed in the enrollment figures.

In addition to the two public schools, the Spanish Catholic Center offers various bilingual educational programs, said Sister Barbara, a volunteer at the center. Classes are offered in secretarial studies, English and home economics for domestics, as well as a bilingual high school equivalency prep course and a class teaching how to fill out forms and applications. The Center also provides youths with counseling about college opportunities.