In this guide, borders are defined in geographic, political, national, linguistic and cultural terms. Sometimes they are clearly defined and other times they are abstract, though still significant to the populations affected by them. During the War of 1812, borders were often unclear as no proper survey had been done to define the boundaries. Border decisions were made by government leaders and frequently led to decades of disagreements. When borders changed, they often affected the people living on either side by determining their nationality and their ability to trade for goods and services.