Clearing Browser History - Comments Page 2

Hi. I've noticed something about my browsing history on certain websites, particularly facebook. History of names that I've searched for show up in the search engine. For example, if I type the letter t, all the names with t's that I've searched for in the past show up, even if I had deleted the history. I've tried deleting history from firefox and internet options. I've tried removing cookies and autocomplete. Nothing has seemed to work! What would you recommend? Thank you for your time!