I suspect that you are not entitled to any compensation. United's contract of carriage (which outlines the terms and conditions you agreed to by buying the ticket) states that
In the event of a Force Majeure Event, UA without notice, may cancel, terminate, divert, postpone, or delay any flight, right of carriage or reservations (whether or not confirmed) and determine if any departure or landing should be made, without any liability on the part of UA. UA may re-accommodate Passengers on another available UA flight or on another carrier or combination of carriers, or via ground transportation, or may refund any unused portions of the Ticket in the form of a travel certificate.
"Force Majeure" is defined in the contract of carriage to include
Any condition beyond UA’s control including, but not limited to, meteorological or geological conditions, acts of God, riots, terrorist activities, civil commotions, embargoes, wars, hostilities, disturbances, or unsettled international conditions, either actual, anticipated, threatened or reported, or any delay, demand, circumstances, or requirement due directly or indirectly to such condition;
As noted by Nate Eldridge in the comments, it is possible that there are local laws in Canada, the USA, or Chile that override this, but I highly doubt it. Even under the extremely flyer-friendly EU compensation laws, you would not be entitled to any compensation if a flight was cancelled due to "extraordinary circumstances that could not have been avoided by any reasonable measure." As a general rule, if the EU wouldn't entitle you to compensation under similar circumstances, no country's law will.
This isn't to say that it would be impossible to get compensation; but you should understand that United is not legally required to do anything for you. If you do request compensation, you will need to frame it in terms of being a loyal customer who suffered extraordinary hardship due to this circumstance (above and beyond the thousands of other United passengers whose travel was disrupted by Hurricane Harvey.) Your best bet if you want to go this route is to contact United's Customer Care center with a brief, articulate letter describing the hardships you incurred and what actions you would like United to take to make you whole. But don't hold your breath.