Complex sentence: Their numbers were increasingly supplemented by students enrolled at nearby Georgetown University and George Washington University, some of whom were exploring their Jewish roots for the first time and found that the close-knit community that Rabbi Rabinowitz nurtured was an ideal setting to do so.
Split into simpler sentences: Their numbers were increasingly supplemented by students enrolled at nearby Georgetown University and George Washington University. Many of these young adults were exploring their Jewish roots for the first time and found that the close-knit community that Rabbi Rabinowitz nurtured was an ideal setting to do so.