MORE: Notable upsets in the Quarterfinals of the US Open Cup (Modern Era)
In 2019, Los Angeles FC broke the Modern Era’s Quarterfinal attendance record in the club’s 1-0 loss to the Portland Timbers at Banc of California Stadium. The announced attendance was 18,947, which narrowly broke the previous record of 17,898 which was set last year in the same stadium, against the same opponent.
That big number for LAFC in 2019, combined with 12,401 at Minnesota United’s win over New Mexico United, it broke the Modern Era’s Quarterfinal record for average attendance for the entire round with 11,525. Elsewhere, Atlanta United drew 7,523 in their 2-0 win over Saint Louis FC (USL-C) and Orlando City SC drew 7,227 in their penalty kick win over New York City FC.
The 2008 US Open Cup marked the first time that a pair of 2nd Division teams advanced out of the Quarterfinals for the second consecutive year.
In 2007, when the Seattle Sounders (USL First Division) defeated the Colorado Rapids (MLS) 5-0, it was the worst loss suffered by an MLS team in the US Open Cup.
In 2007, the USL First Division (2nd Division) had three teams in the Quarterfinals (Carolina, Charleston, Seattle), the most ever. That same year, only three MLS teams advanced to the Quarterfinal round, the fewest ever. For the first time ever, two USL Second Division (3rd Division) teams (Richmond Kickers, Harrisburg City Islanders) made the round of eight in the same year. In 2010, a pair of USL-2 clubs advanced to the Quarterfinals (Charleston Battery, Harrisburg City Islanders) in the same year.
2012 marks the first year in the Modern Era that three Division 3 clubs reached the Quarterfinals with the Harrisburg City Islanders, Dayton Dutch Lions and the Charlotte Eagles all playing in the Round of Eight.
The Carolina RailHawks and the Seattle Sounders won their Quarterfinal matches in 2007, marking only the second time that two USL First Division (2nd Division) teams had done that in the same year. In 1999, the Charleston Battery and the Rochester Raging Rhinos both made the Semifinals, with Rochester eventually winning the tournament.
The Second Division of US Soccer has been represented in the Quarterfinals by at least one team in all but five tournaments (2000, 2006, 2010, 2012, 2015). In 2010, it was the first year that the Quarterfinals were without Second Division representation but there were still USL Second Division (3rd Division of US Soccer) remaining: Charleston Battery and the Harrisburg City Islanders.
The Harrisburg City Islanders are the first Third Division team to ever reach the Quarterfinals in consecutive seasons (2009, 2010). 2010 also marked the first time that two USL-2 clubs (Third Division) reached the Quarterfinals two years in a row. (Wilmington & Harrisburg in 2009, Charleston & Harrisburg in 2010).
FC Dallas have the most Quarterfinals appearances among all Major League Soccer teams.
| 16 | FC Dallas | 8-7-1 (1-0) | 1996^ 1997^ 1998^ 1999 2000 2002^ 2004 2005^ 2006 2007^ 2008 2011^ 2013, 2014^ 2016^ 2017 |
| 14 | Chicago Fire | 11-1-2 (2-0) | 1998^ 2000^ 2001^ 2003^ 2004^ 2005^ 2006^ 2008 2011^ 2013^ 2014^ 2015^ 2016^ 2018^ |
| 12 | LA Galaxy | 6-5-1 (1-0) | 1999 2000^ 2001^ 2002^ 2003^ 2005^ 2006^ 2010 2011 2015 2016^ 2017 |
| 11 | DC United | 9-1-1 (0-1) | 1996^ 1997^ 2000 2001^ 2003^ 2005 2006^ 2008^ 2009^ 2010^ 2013^ |
| 11 | Sporting Kansas City | 5-5-1 (0-1) | 1996 2002^ 2004^ 2005 2008 2009 2011 2012^ 2015^ 2017^ 2018 |
| 9 | NE Revolution | 2-5-2 (2-0) | 2001^ 2003 2006 2007^ 2008^ 2013 2014 2016^ 2017 |
| 9 | New York Red Bulls | 4-3-2 (1-1) | 1997^ 1998^ 2000^ 2002 2003^ 2006 2011 2015 2017^ |
| 9 | San Jose Earthquakes | 1-5-3 (1-2) | 1997 1998 2000 2001 2002 2004^ 2005 2012 2017^ |
| 7 | Columbus Crew | 4-2-1 (0-1) | 1998^ 1999^ 2000 2001 2002^ 2004 2010^ |
| 6 | Colorado Rapids | 2-4-0 | 1996^ 1999^ 2002 2003 2006 2007 |
| 6 | Houston Dynamo | 3-3-0 | 2006^ 2009^ 2010 2015 2016 2018^ |
| 6 | Seattle Sounders | 5-1-0 | 2009^ 2010^ 2011^ 2012^ 2014^ 2016 |
| 5 | Philadelphia Union | 3-0-2 (1-1) | 2012^ 2014^ 2015^ 2016 2018^ |
| 4 | Tampa Bay Mutiny | 0-4-0 | 1996 1997 1998 1999 |
| 4 | Portland Timbers | 2-2-0 | 2013^ 2014 2018 2019^ |
| 3 | Real Salt Lake | 2-1-0 | 2011 2013^ 2015^ |
| 2 | Chivas USA | 2-0-0 | 2010^ 2012^ |
| 2 | Miami Fusion | 1-1-0 | 1998 2000^ |
| 3 | Orlando City SC | 0-2-1 (1-0) | 2015 2018, 2019^ |
| 2 | Los Angeles FC | 1-1-0 | 2018^, 2019 |
| 1 | Atlanta United FC | 1-0-0 | 2019^ |
| 1 | Minnesota United FC | 1-0-0 | 2019^ |
| 1 | New York City FC | 0-1-0 | 2019 |
^ Advanced in their Quarterfinal match
The Charleston Battery have the most lower division Quarterfinal appearances since 1996.
| 6 | Charleston Battery | 3-3-0 | 1999^ 2004^ 2007 2008^ 2009 2010 |
| 5 | Rochester Rhinos | 3-1-1 (0-1) | 1996^ 1999^ 2004 2005 2009^ |
| 4 | Richmond Kickers | 1-3-0 | 2001 2004 2007 2011^ |
| 4 | Seattle Sounders | 1-2-1 (1-0) | 1996 2003 2007^ 2008^ |
| 4 | H’burg City Islanders | 0-4-0 | 2007 2009 2010 2012 |
| 3 | Carolina RailHawks | 1-2-0 | 2007^ 2013 2014 |
| 2 | Minnesota Thunder | 1-0-1 (0-1) | 2004 2005^ |
| 2 | Wilm. Hammerheads | 0-2-0 | 2003 2009 |
| 1 | Atlanta Silverbacks | 0-1-0 | 2014 |
| 1 | Carolina Dynamo | 0-1-0 | 1996 |
| 1 | Charlotte Eagles | 0-1-0 | 2012 |
| 1 | Chicago Stingers | 0-1-0 | 1997 |
| 1 | Crystal Palace Baltimore | 0-0-1 (0-1) | 2008 |
| 1 | Dayton Dutch Lions | 0-1-0 | 2012 |
| 1 | Ft. Lauderdale Strikers | 0-1-0 | 2016 |
| 1 | L.I. Rough Riders | 0-1-0 | 1997 |
| 1 | Louisville City FC | 0-1-0 | 2018 |
| 1 | Milwaukee Rampage | 0-1-0 | 2002 |
| 1 | Nashville Metros | 0-1-0 | 1998 |
| 1 | New Mexico United | 0-1-0 | 2019 |
| 1 | Orlando City SC | 0-1-0 | 2013 |
| 1 | Pittsburgh Riverhounds | 0-1-0 | 2001 |
| 1 | Saint Louis FC | 0-1-0 | 2019 |
| 1 | San Fran. Bay Seals | 1-0-0 | 1997^ |
| 1 | Staten Island Vipers | 0-1-0 | 1999 |
| 1 | FC Cincinnati | 1-0-0 | 2017^ |
| 1 | Miami FC (NASL) | 0-1-0 | 2017 |
^ Advanced in their Quarterfinal match