Arthur Andersen fell off the big 5 accounting firms ranking in 2002 after they were found guilty of obstructing justice in the Enron Scandal. The conviction was later overturned, but the damage was done.
It started in 1913 by Northwester University professor named Arthur Andersen.
Arthur Andersen was a global professional services firm just like the other big 5. They notoriously became to close to one of their clients, Enron, who falsely reported revenues. They infamously shredded a lot of documents related to the audit of Enron.
Arthur Andersen was also famous for the growth of their consulting business. The consulting firm eventually spun off and rebranded as Accenture.
After Enron, most of the big accounting firms spun off their consulting operations to appease regulators who said the consulting businesses interfered with independence.
Now all of the big 4 accounting firms have established and grown their consulting businesses to huge contributors to their revenue.
Their revenues before they went under approached $10 billion.