How to use "strengthen" in a sentence

To strengthen, perpetuate, and extend this interest was the object for which the insurgents would rend the Union, even by war; while the government claimed no right to do more than to restrict the territorial enlargement of it

To that world assembly of sovereign states, the United Nations, our last best hope in an age where the instruments of war have far outpaced the instruments of peace, we renew our pledge of support - to prevent it from becoming merely a forum for invective - to strengthen its shield of the new and the weak - and to enlarge the area in which its writ may run.