Try using this by replacing the double quotation by single quotation:
var datepickerFrom = new Pikaday(
{
field: document.getElementById('datepickerFrom'),
firstDay: 1,
format: 'mm/dd/yyyy',
minDate: new Date('1900-01-01'),
maxDate: new Date('2040-12-31'),
yearRange: [1900, 2040]
});