He was born in Dessau, Germany, the only son of Frederick William and Louisa Henrietta Schultz Vandersloot. He graduated from the University of Leipsig. He emigrated to the United States in 1801, landing in Charleston, SC. He placed an advertisiment in the Philadelphia, PA newspaper looking for his father. He migrated to Northampton County, PA where his father was a Reformed pastor. He married Catherine Deiser Pauli, whose father was a Reformed pastor in Reading, PA on November 11, 1802. Frederick William, Jr. was ordained by the German Reformed Church in 1803. He served a ten church charge in Northampton and Lehigh counties, PA until 1812. He served the Goshenhoppen charge until 1819 when he moved to Salem Reformed church, Philadelphia, PA. He built a new church there but the young congregation could not pay his salary so he moved to a multiple church charge in Rockingham County, VA in 1823. In 1827 he was called to a nine church charge in York and Adams Counties, PA.

The Vandersloots had 6 sons and 7 daughters: Frederick, Maria, Ferdinand, Caroline, Charles, Magdalena, Wilhelmina(1814-17), Gustav, Catherine (1817-19), John, Emma, infant (1824-24), and Henry. Two of their sons became Reformed ministers. Two of their sons disappeared. Charles Augustus (1810- ) joined the army in August 1840. He was sent to Fort Leavenworth, KS. He deserted in January 1841. The family never heard from him after 1844. He left a wife and three children: Frederick (97283704), Ferdinand (39712585)and Mary J. Vandersloot. Son John Theodore (1819- ) disappeared, he supposedly went to sea.

Frederick William was musical, a poet and a linguist. His final words (translated from the German) were "I hear the holy angels of God in Heaven singing. [See "History and Genealogy of the Von Der Sloot Family", pp. 18-28, Lewis Vandersloot, 1901.]