JSFiddle - React, Tailwind, and code Playground

HTML

<select name="ddState" id="ddState">
    <option value="">--Select--</option>
    <option value="AB">Alberta</option><option value="BC">British Columbia</option><option value="MB">Manitoba</option><option value="NB">New Brunswick</option><option value="NL">Newfoundland</option><option value="NS">Nova Scotia</option><option value="NT">Northwest Territories</option><option value="NU">Nunavut</option><option value="ON">Ontario</option><option value="PE">Prince Edward Island</option><option value="QC">Quebec</option><option value="SK">Saskatchewan</option><option value="YT">Yukon</option></select>

JavaScript

var StateToSelect = "IL";
var mStateDDToUpdate = 'ddState';
var result = '[{"Key":"AK","Value":"Alaska                        "},{"Key":"AL","Value":"Alabama                       "},{"Key":"AR","Value":"Arkansas                      "},{"Key":"GA","Value":"Georgia                       "},{"Key":"HI","Value":"Hawaii                        "},{"Key":"IA","Value":"Iowa                          "},{"Key":"ID","Value":"Idaho                         "},{"Key":"IL","Value":"Illinois                      "},{"Key":"IN","Value":"Indiana                       "},{"Key":"KS","Value":"Kansas                        "},{"Key":"KY","Value":"Kentucky                      "},{"Key":"LA","Value":"Louisiana                     "},{"Key":"WY","Value":"Wyoming                       "}]';


// Remove all the options except --Select--
while($("#" + mStateDDToUpdate + " option").size() > 1) {
    $("#" + mStateDDToUpdate + " option:eq(1)").remove();
}
try {
    var options = JSON.parse(result);
    for (var i = 0; i < options.length; i++) {
       $("#" + mStateDDToUpdate).append("<option value='" + options[i].Key.trim() + "' >" + options[i].Value.trim() + "</option>");                
    }
    // Pick the state (retrieved earlier) from the new list.
    if (typeof StateToSelect != 'undefined' && StateToSelect != null) {
        $("#" + mStateDDToUpdate).val(StateToSelect);
    }
} catch (ex) {
    alert("Error setting the state list.\r\n" + ex.message + "\r\n" + result);
}