▁" t ro pe ir ismo " ▁( T ro op ing ), ▁as ▁a ▁rest ing ▁point ▁of ▁the ▁cattle ▁deal ers , ▁who ▁were ▁mount ing ▁groups ▁and ▁villages ▁for ▁the ▁landing , ▁before ▁they ▁travel ▁towards ▁the ▁South . ▁The ▁first ▁nucle us ▁of ▁cattle ▁deal ers ▁in ▁the ▁region ▁of ▁It ap et ining a ▁appeared ▁in ▁ 1 7 2 4 , ▁when ▁it ▁was ▁discovered ▁that ▁the ▁past ure ▁in ▁the ▁region ▁was ▁abund ant ▁and ▁the ▁land ▁was ▁fert ile ▁for ▁plant ing . ▁To ▁these ▁factors ▁there ▁was ▁added ▁up ▁the ▁distance ▁to ▁the ▁Sor oc aba ▁town ▁- ▁ 1 2 ▁le agues ▁- ▁that ▁was ▁corresponding ▁to ▁a ▁journey ▁of ▁a ▁tro op . ▁About ▁ 1 7 6 0 , ▁a ▁group ▁of ▁Portuguese , ▁led ▁by ▁Dom ing os ▁José ▁Vie ira , ▁left ▁the ▁first ▁nucle us ▁( today , ▁district ▁of ▁Porto ) ▁and ▁formed ▁another , ▁in ▁a ▁ ▁high ▁place ▁and ▁surrounded ▁by ▁two ▁streams . ▁ ▁At ▁this ▁time ▁there ▁was ▁an ▁argument ▁between ▁two ▁nucle uses ▁that ▁wanted ▁to ▁be ▁elev ated ▁to ▁the ▁condition ▁of ▁town . ▁The ▁results : ▁in ▁April ▁ 1 7 , ▁ 1 7 7 0 , ▁Sim ão ▁Barb osa ▁Franco ▁was ▁nominated ▁to ▁establish ▁and ▁admin ister ing ▁the ▁new ▁village , ▁and ▁so ▁was ▁left ▁to ▁him ▁the ▁choice ▁of ▁the ▁principal ▁nucle us . ▁Histor ians ▁tell ▁that ▁a ▁" m arch ing " ▁m