Here's a link that hopefully helps you:
https://www.smithsonianmag.com/smart-news/five-things-know-about-declaration-sentiments-180959352/
<span>The Declaration of Independence is primarily a formal declaration of "separation" issued by the United States against Great Britain, after Britain failed to meet the demands of the colonists regarding taxation. </span>
In general, yes, immigration during 1830s to 1840s was vital to the industrialization of America, since it was mostly immigrants who first sought employment in the factories that were an essential element of industrialization.
