Hello. You did not submit the text to which this question refers, which makes it impossible for this question to be answered. However, I will try to help you as best I can.
A textual evidence is a statement that proves an argument or information presented by the author of a text. This statement explains why the information in the text is correct, how events presented in the text happened and even confirm facts and justify ideas presented in the text. In this case, to answer your question, you will have to read all the text that is related to it and identify the sentences that try to explain and show how the territorial expansion in 1840 happened. This evidence can be considered good and effective, if it presents historically proven justifications for territorial expansion, going so far as to prove to the reader that this expansion, in fact, happened, and presenting the reasons that established it.
From 1863 and 1869, roughly 15,000 Chinese workers helped build the transcontinental railroad. Chinese workers made up most of the workforce between roughly 700 miles of train tracks between Sacramento, California, and Promontory, Utah.
The fundamental motif through all the centuries has been the principle that force and power are the determining factors. ... Force is the first law. A struggle has already taken place between original man and his primeval world. Only through struggle, have states and the world become great.
