Adding USA at the top of dropdown list of countries. OK practice or not?

1. What would be the probable reason to add drop down menu to your website?
2. How many items should be in a drop down?
3. How many items is too many for a dropdown?

What would be the probable reason to add drop down menu to your website?

The use case for drop-down menus

They also help conserve screen space. Offering drop-down menus can help users avoid scrolling and can quickly get them access to your site's content. For large websites, drop-down menus can save users time by allowing them to jump down a level or two to get to the content they seek.

How many items should be in a drop down?

Choosing Between a Listbox and a Dropdown List. Compared to using standalone checkboxes or radio buttons, it's better to use a listbox or dropdown list when there are 5 or more items from which users can choose.

How many items is too many for a dropdown?

In General, Avoid Drop-Downs When There Are More Than 10 or Fewer Than 5 Options. Drop-downs quickly become difficult for users when they are presented with an overwhelming number of options to choose from.