▁M ansion ▁National ▁Historic ▁Site ▁is ▁one ▁of ▁the ▁area ' s ▁oldest ▁Hudson ▁River ▁est ates . ▁The ▁earliest ▁development ▁of ▁the ▁estate ▁began ▁in ▁ 1 7 6 4 ▁when ▁Dr . ▁John ▁B ard ▁purchased ▁land ▁on ▁the ▁east ▁side ▁of ▁the ▁Alb any ▁Post ▁Road , ▁where ▁he ▁built ▁Red ▁House ▁and ▁developed ▁the ▁agricult ural ▁aspects ▁of ▁the ▁eastern ▁section ▁of ▁the ▁property ▁that ▁continued ▁through ▁Frederick ▁and ▁Louise ▁V ander b ilt ' s ▁occup ancy . ▁B ard ▁family ▁ownership ▁continued ▁through ▁ 1 8 2 1 ▁with ▁his ▁son , ▁Dr . ▁Samuel ▁B ard ▁( 1 7 4 2 – 1 8 2 1 ), ▁ow ning ▁the ▁property ▁from ▁ 1 7 9 9 ▁to ▁ 1 8 2 1 . ▁In ▁ 1 8 2 8 , ▁Dr . ▁David ▁H os ack , ▁president ▁of ▁the ▁New ▁York ▁H ort icult ural ▁Society , ▁purchased ▁the ▁property ▁from ▁Samuel ▁B ard ' s ▁he irs , ▁with ▁André ▁Par ment ier ▁helping ▁to ▁design ▁the ▁grounds . ▁In ▁ 1 8 4 0 , ▁John ▁Jacob ▁Ast or ▁purchased ▁the ▁property ▁from ▁H os ack ' s ▁he irs ▁for ▁his ▁daughter ▁Dor othe a ▁and ▁her ▁husband ▁Walter ▁S . ▁Lang don . ▁Their ▁son ▁Walter ▁inherited ▁and ▁occupied ▁the ▁estate ▁to ▁the ▁time ▁of ▁his ▁death ▁in ▁ 1 8 9 4 . ▁ ▁Frederick ▁and ▁Louise ▁V ander b ilt ▁purchased ▁Hy de ▁Park ▁in ▁May ▁ 1