Why did the framers establish six year terms for senators?

The men who framed the United States Constitution created a tow house legislative body. They determined that one of the houses should be elected every tow years and the other house, the Senate, every six years. They wanted this group to serve longer in order to have continuity in the legislature and avoid a complete turnover every election like the House of Representative. The Senators wouldn't have to spend all their time planning how to get elected every two years.