As flocks of people pass me bypass by me with carts full of fried maize, tacos, and tamales, and children with colorful attires trot along selling Virgin of Guadalupe sculptures and paintings, and before I go into customs , I take a last glance at the city's dynamism, the merge of cultures, and the different backgrounds that make my border town (When you say "make my border town," it makes me expect an adjective to follow that, ie "makes my border town Mexicali great." Maybe say "that comprise my border town" or "that make up my border town) , Mexicali, home to a myriad of immigrants before I go through customs .
This is a very long sentence, and your thoughts might get lost by the end.
its attachment will promise an opportunity to become invisible
This is slightly confusing. If the rope is successfully attached, won't opportunity become tangible/real, not invisible?
dreams fading away along with daylight as the day closes on us all
"dreams fade away with the daylight as night approaches." The night part is just a suggestion, but I think it adds to the illustration of day fading and night coming in
With the best of intentions, and in attempt to uphold their family, illegal immigrants from middle and southern America try to provide a better future for their children
Maybe say something like "These illegal immigrants from middle and southern America have the best of intentions; they want to uphold their family by providing a better future for their children."
but lose their
they also lose their...
This is a very interesting take on the prompt. I don't think there will be many essays like yours, which is very good! Helpful hint: You can also use this for college prompts that as about a world event and how you feel about it, a local event and how you feel about it, and you could also spin this to answer a question about diversity. You have a very flexible essay, good job!