Are you looking for a specific word? The answer is border but I see you've included this in your question so I believe you do not understand the concept.
The main cause of the second industrial revolution was, natural resources, abundant labor supply, strong government policy and new sources of power.
Texas was annexed by the United States in 1846 and war broke out again with Mexico, Lamar joined the U.S. Army. He fought in the battle of Monterrey and helped organize a municipal government in Laredo. In his later years, Lamar traveled, wrote poetry, and spoke out in support of slavery in the South.
