▁offered ▁for ▁sale ▁in ▁ 2 0 1 6 ▁for ▁$ 6 5 , 0 0 0 . ▁Map ▁making ▁at ▁that ▁time ▁was ▁important ▁for ▁both ▁Mexico ▁and ▁the ▁United ▁States . ▁ ▁The ▁Green wich ▁prime ▁mer id ian ▁became ▁the ▁international ▁standard ▁reference ▁for ▁cart ograph ers ▁in ▁ 1 8 8 4 . ▁ ▁Tw enti eth ▁century ▁During ▁the ▁ 2 0 th ▁century , ▁maps ▁became ▁more ▁abund ant ▁due ▁to ▁improvements ▁in ▁printing ▁and ▁phot ography ▁that ▁made ▁production ▁che aper ▁and ▁easier . ▁Air plan es ▁made ▁it ▁possible ▁to ▁photograph ▁large ▁areas ▁at ▁a ▁time . ▁ ▁Two - Point ▁Equ id istant ▁projection ▁was ▁first ▁drawn ▁up ▁by ▁Hans ▁Ma urer ▁in ▁ 1 9 1 9 . ▁In ▁this ▁projection ▁the ▁distance ▁from ▁any ▁point ▁on ▁the ▁map ▁to ▁either ▁of ▁the ▁two ▁reg ulating ▁points ▁is ▁accurate . ▁ ▁The ▁lo xim uth al ▁projection ▁was ▁constructed ▁by ▁Karl ▁S iem on ▁in ▁ 1 9 3 5 ▁and ▁ref ined ▁by ▁Wal do ▁Tob ler ▁in ▁ 1 9 6 6 . ▁ ▁Since ▁the ▁mid - 1 9 9 0 s , ▁the ▁use ▁of ▁computers ▁in ▁map ▁making ▁has ▁helped ▁to ▁store , ▁sort , ▁and ▁ar range ▁data ▁for ▁mapping ▁in ▁order ▁to ▁create ▁map ▁pro jections . ▁ ▁Contempor ary ▁▁ ▁Software ▁development ▁ ▁Now ad ays ▁map ▁making ▁heavily ▁re lies ▁on ▁computer ▁software ▁to ▁develop ▁and ▁provide ▁a ▁variety ▁of ▁services , ▁a ▁tr