They were among the first to develop a system of uniform weights and measures. Their building bricks w<span> This was the first civilization to incorporate urban sanitation systems. Personal hygiene seems to have been a high priority. </span>ere very uniform making city planning easy. <span> Transportation and trade were major goals of these people. Their trade network ran from Mesopotamia to northern and central India. Their empire was economic, not military. </span>
Mexican immigrants wanted to escape poverty, war, turmoil, and even persecution for certain groups