Spotlighting a History of Slavery in N.Y.C. It’s Friday. Weather: Sunny morning, cloudy afternoon and a high in the mid-60s. Occasional showers and mid-50s on Saturday. Mother’s Day starts nice but turns threatening, high in the mid-60s. Alternate-side parking: In effect until Thursday (Solemnity of the Ascension). Image Nostrand Avenue. Boerum Hill. Prospect Lefferts Gardens. They’re well-known Brooklyn roads and neighborhoods, among those across the city that draw their name from influential families of the past. But less familiar are the ties those families had to slavery. A new campaign called Slavers of New York is aiming to change that by calling out — and eventually mapping — the history of slavery in New York City. The effort highlights the streets, subway stations and neighborhoods named after enslavers.