▁ 1 9 4 3 , ▁Ro ose vel t ' s ▁Secret ▁Service ▁was ▁hous ed ▁in ▁the ▁bas ement ▁and ▁third - floor ▁service ▁areas , ▁and ▁some ▁of ▁the ▁President ' s ▁personal ▁White ▁House ▁staff ▁and ▁friends ▁occasionally ▁stayed ▁in ▁the ▁main ▁bed rooms ▁of ▁the ▁house , ▁including ▁those ▁of ▁Frederick ▁and ▁Louise ▁V ander b ilt . ▁ ▁M ansion ▁▁ ▁The ▁ 5 4 - room ▁m ansion ▁is ▁the ▁work ▁of ▁the ▁architect ural ▁firm ▁McK im , ▁M ead ▁& ▁White . ▁Charles ▁Fol len ▁McK im ▁designed ▁the ▁plan ▁in ▁the ▁Be aux - Ar ts ▁style ▁and ▁Stan ford ▁White ▁assist ed ▁as ▁an ▁anti ques ▁bu yer . ▁ ▁The ▁house ▁has ▁a ▁classic ▁Be aux - Ar ts ▁plan , ▁with ▁the ▁major ▁public ▁rooms ▁on ▁its ▁ground ▁floor ▁– ▁the ▁central ▁Elli pt ical ▁Hall , ▁D ining ▁Room , ▁and ▁Living ▁Room ▁– ▁all ▁in ▁one ▁line , ▁parallel ▁to ▁the ▁Hudson ▁River . ▁North ▁and ▁South ▁F oy ers ▁provide ▁trans itional ▁space ▁from ▁the ▁Hall ▁to ▁the ▁D ining ▁Room ▁and ▁Living ▁Room . ▁Five ▁secondary ▁spaces ▁are ▁located ▁off ▁the ▁Elli pt ical ▁Hall : ▁the ▁Lob by , ▁Den , ▁Gold ▁Room , ▁Grand ▁St air ▁Hall , ▁and ▁Lav atory . ▁The ▁second ▁floor ▁rooms , ▁compr ising ▁Mrs . ▁V ander b ilt ' s ▁suite ▁of ▁Bed room , ▁Bou do ir ▁and ▁Bath room ▁( des igned ▁by ▁Og den