After stu­dy­ing at Co­lum­bia Uni­ver­sity, Has­tings en­t­e­red the Ecole des Beaux-Arts in Paris, being gra­dua­ted in 1884. On his re­turn to New York, he en­t­e­red the of­fice of McKim, Mead & White, but soon for­med the part­nership of Car­rere & Has­tings. At the be­gin­ning of the firm's his­tory, it es­ta­blis­hed its high re­pu­ta­tion with the Ponce de Leon Hotel at St. Au­gus­tine, Flo­rida. The New York Pu­blic Li­brary, Fifth Ave­nue and 42nd Street; the in­te­rior of the Me­tro­po­li­tan Opera House; ap­proa­ches and de­co­ra­ti­ons of the Man­hat­tan Bridge; Cen­tury Thea­ter; Vic­tory Arch, Ma­di­son Square, 1918; St. Am­brose Cha­pel in the Ca­the­dral of St. John the Di­vine; and a num­ber of im­portant re­si­den­ces are among the firm's achie­ve­ments. Mr. Has­tings de­si­gned the me­mo­rial am­phi­thea­ter in Ar­ling­ton Ce­me­tery where the Un­k­nown Sol­dier is bu­ried; the pe­des­tal of the sta­tue of Laf­ay­ette in the Court of the Lou­vre, Paris; the Ame­ri­can Em­bassy and De­vonshire House in Lon­don; the Se­nate and House of Re­pre­sen­ta­ti­ves of­fice buil­dings in Wa­shing­ton; and the Ame­ri­can mo­nu­ment in Paris com­me­mo­ra­ting the de­feat of the Ger­mans at the Marne. Among the ho­nors bes­to­wed upon him were the de­grees of LL.D. from the Uni­ver­sity of Li­ver­pool and Laf­ay­ette, the Royal Gold Medal of the Royal In­sti­tute of Bri­tish Ar­chi­tects, and mem­bership in the Le­gion of Honor and in the In­sti­tute of France. He was a trus­tee of the Aca­demy of Arts and Let­ters, a for­mer pre­si­dent of the Beaux- Arts In­sti­tute of De­sign, se­veral times a di­rec­tor of the Ame­ri­can In­sti­tute of Ar­chi­tects, chair­man of the Sar­dis Ex­plo­ra­tion So­ciety Com­mis­sion, trus­tee and secretary-general of the Mu­seum of French Arts, for­mer pre­si­dent of the So­ciety of Beaux-Arts Ar­chi­tects, a foun­der of the Fe­deral Art Com­mis­sion, and for­mer pre­si­dent of the Ar­chi­tec­tu­ral Le­ague of New York.