▁B anc ro ft ▁planned ▁to ▁include ▁the ▁copy ▁in ▁Aut ograph ▁Le aves ▁of ▁Our ▁Country ' s ▁Auth ors , ▁which ▁he ▁planned ▁to ▁sell ▁at ▁a ▁Sold iers ' ▁and ▁S ail ors ' ▁San it ary ▁Fair , ▁in ▁Baltimore , ▁to ▁raise ▁money ▁to ▁care ▁for ▁the ▁Union ▁Army . ▁ ▁B anc ro ft ▁was ▁elected ▁an ▁Associ ate ▁Fellow ▁of ▁the ▁American ▁Academy ▁of ▁Arts ▁and ▁Sciences ▁in ▁ 1 8 6 3 . ▁In ▁ 1 8 6 6 , ▁he ▁was ▁chosen ▁by ▁Congress ▁to ▁deliver ▁the ▁special ▁e ul ogy ▁on ▁Lincoln . ▁ ▁In ▁ 1 8 6 7 , ▁President ▁Andrew ▁Johnson ▁offered ▁B anc ro ft ▁the ▁post ▁of ▁US ▁minister ▁to ▁Pr uss ia , ▁en abling ▁him ▁to ▁return ▁to ▁Germany . ▁B anc ro ft ▁remained ▁in ▁Berlin ▁for ▁seven ▁years , ▁and ▁President ▁U ly ss es ▁S . ▁Grant ▁appointed ▁him ▁minister ▁to ▁the ▁German ▁Empire ▁in ▁ 1 8 7 1 . ▁During ▁his ▁ten ure ▁in ▁Berlin , ▁B anc ro ft ▁spent ▁much ▁time ▁negoti ating ▁agre ements ▁with ▁Pr uss ia ▁and ▁the ▁other ▁north ▁German ▁states ▁rel ating ▁to ▁natural ization ▁and ▁citizens hip ▁issues ; ▁they ▁became ▁known ▁as ▁the ▁B anc ro ft ▁Tre aties ▁in ▁his ▁honor . ▁The ▁treat ies ▁were ▁the ▁first ▁international ▁recognition ▁of ▁the ▁right ▁of ▁exp atri ation . ▁The ▁principle ▁has ▁since ▁incorpor ated ▁in ▁the ▁law ▁of ▁nations . ▁