The 112th Congress is on track to be the least productive in modern history, as partisan wrangling between the Republican-led House, the Democratic-run Senate and President Barack Obama has taken its toll on legislative action.

During the first session of the 112th Congress, the House and the Senate each passed the fewest number of bills in any Congress since 1947, when statistics about lawmaking activity began being compiled.

In addition, the number of laws enacted was 90, two more than the previous low of 88 in the 104th Congress in 1995.

The pace in the 112th’s second session has, if anything, slowed further.

As of July 31, the House has passed 636 measures, including bills and resolutions, while the Senate has passed 635 measures for a total of 1,271. The previous low for total measures passed is 1,834 in the 104th Congress.

In the first session of the 112th Congress, the House was in session 175 days and the Senate 170 days, both of which are above-average days for the first sessions of Congresses.

“Differences have always existed between the House and Senate, even when the same party controls the majority in both of them, but those differences balloon when they are divided between parties,” Senate Historian Donald Ritchie said.

The parties have blamed each other for not taking up bills passed by one chamber, particularly those they argue would spur economic growth.

“The House has passed more than 30 jobs bills that are being blocked by Senate Democrats. … We’ve done our job. Senate Democrats have no excuses,” said Kevin Smith, a spokesman for Speaker John Boehner (R-Ohio).

Senate Majority Leader Harry Reid (Nev.) and other Democratic leaders have accused Republicans of obstructing Democratic bills for political gain at the expense of the economy.

However, other recent periods of divided government saw bursts of lawmaking activity.

For instance, in the 110th Congress, then-Speaker Nancy Pelosi (D-Calif.) and the House passed more bills in 2007, 560, than any House had passed in its first session since 1967. At the time, Democrats controlled both chambers of Congress and Republican President George W. Bush was in the White House.

Even taking into account bills the House and Senate are expected to pass in the upcoming lame-duck session, the current Congress could easily have the lowest level of legislative activity since statistics began being tabulated.

The Résumé of Congressional Activity, published in the Congressional Record, was established in 1947, during the infamous “do nothing” Congress that President Harry Truman criticized en route to his against-the-odds victory in 1948.

But by today’s standards, the 80th Congress was extremely busy, having passed 4,132 measures, more than the measures passed by every Congress since 1963. Over time, statistics show, Congress has generally passed fewer bills, and fewer laws have been signed into law.

Like the 112th Congress, the 104th Congress was besieged by partisan gridlock.

Another Congress marked by inactivity was the 97th in 1981-1982, the first two years of President Ronald Reagan’s term. In that Congress, Republicans took control of the Senate, the first time the GOP had enjoyed a majority in a Congressional chamber since the 1950s.

“The American constitutional system makes it hard to enact legislation under any circumstances, given two houses of Congress that are structured differently, a president who can veto or threaten to veto legislation, and courts that can rule laws unconstitutional,” Ritchie said, adding, “It becomes all the more difficult when the parties are polarized and in control of opposite bodies.”

The number of bills passed in the first session of the 112th Congress, the lowest ever, is about one-third of the average number of bills passed in first sessions of Congresses and less than half of the median number passed in the first sessions of Congresses since 1947.

The Senate has passed the fewest percentage of House bills (32.4 percent) of any Senate during that time period. The House has passed 40.4 percent of Senate bills, which is the fourth-lowest percentage for the same time period.

The Senate of the 112th Congress has held 421 roll-call votes as of July 31. That compares with 657 in the 110th Congress and 919 in the 104th Congress. But the figure is significantly higher than the 248 roll-call votes taken in the 80th Congress.

The House of the 112th Congress has held 444 roll-call votes, compared with 1,120 in the 110th Congress, 522 in the 104th Congress and 163 in the 80th Congress.

Critics have seized on the activity levels as a sign of dysfunction, but advocates for smaller government have noted that a more active Congress is not necessarily a good thing.

“A lot of the Congressional activity in past decades focused on increasing spending and creating more and more government programs. We have no intention of doing that,” Boehner spokesman Smith said.

The 112th Congress isn’t over yet, though, and unfinished business is likely to make for a busy lame-duck session in December, which could push up the numbers.