The second American civil war– Indy/CART split
In April of 1861, the Northern and Southern governments of the no-longer 'United' States began fighting what would become one of the bloodiest wars in the history of the nation. It was a long dark night, but ultimately, the north prevailed, and preserved the union.
It would be 135 years until the next civil war in the states, and while the latter of the two didn't cost any lives, it was destructive in its own right, with no unity left when the dust settled, and the greatest racing series of American history in ruins.
The protagonist in the former war was Abraham Lincoln, but in the latter, it was the equally-powerful king of the Indianapolis Motor Speedway, Tony George, who decided to secede from CART due to rising costs, and take the Indy 500 with him, to form his own adaptation of American open-wheeled racing- the Indy Racing league, for the 1996 season and on.
Pinetrest- 1997 Indy 500- Indy Racing League
America had entered its second long, dark night. The US's royalty, CART, had it's crown, but no jewel, and the opposite was true for their wannabe-royalty, who had the jewel, but lacked a crown.
CART, in dire need of a that 'jewel' flagship race, had to make do with the US 500 held at a lesser-known oval near their headquarters, but the series would never be the same. The US 500 lacked the support of the Indy Racing League's home race, and it's attempts to replicate old traditions didn't sit well with fans, who preferred the real-deal, rather than the 'made in China' knock-off.
They began to suffer, losing fans and money, as well as drivers and teams, causing their finances to tumble. Without the Indy 500, CART was merely 'a motorsport series'. No more, no less.
Even with the benefit of the Indy 500, however, IRL's (Indy racing league's) management and drivers were laughable, with ex-CART failures being front-of-the-field in the George-run series, and poor decisions at the top leading to chaos within the CART alternative.
A near-sponsor-less IRL car in 2002
Both sides were losing the battle, but, surprisingly, CART was the first to show signs of illness, following disaster 2001 and 2002 seasons, in which several races were cancelled, and the series' bold move into Europe was nearly thwarted by the tragic 9/11 attacks.
CART's infrastructure was dwindling fast, with their drivers moving to the now more-popular IRL, and F1. As drivers, sponsorship revenue, and viewer numbers fell after ESPN and ABC ditched, the problem worsened exponentially, and ultimately, even Team Penske, who had stuck with CART since its birth, jumped ship.
The once-famous series declared bankruptcy post the 2003 season, but were saved by a consortium. Still, losing their title sponsor, they were forced to rename to 'Champ Car'. Rebranding did nothing, however, and CART's problems grew more and more evident as years passed, making even IRL look put-together, despite their problems being equally difficult, as even their teams began leaving, despite the big players joining years earlier.
By the time 2008 arrived, open-wheel racing in America was hurting, as both sides were falling apart, and neither thought they had enough cars for a successful season. IRL and CART agreed to finally merge, and while not graceful in the early stages, the two became fully integrated later on.
Still, in similar fashion to the first Civil War, peace was not the end of the road. Reconstruction had just begun, and this proved the most difficult task. The destruction caused by the split took years to remedy, and the newly-formed 'Indycar series' felt the effects all the way through to 2018, when they finally seemed to get their rules right, and sort their platform.
But even still, this is not the end. Just recently, one of the original members of CART, Roger Penske, purchased Indycar, and there is hope that this will be the first step to recreating the dominant all-powering American motorsport that CART once was. And, barring the chance that he bans the Indy 500 (which he owns) from Indycar (which he owns), I think you can be sure he'll do just that.