I can give you the short-and-dirty in brief points, Simon_Jester.
-Late 22nd century; ICR is hastily founded for mutual protection/economic benefit; a typical capitalist presidential republic.
-31st-33rd century; Things go downhill as the republic starts rattling apart: widespread unrest and violence, calls for reform, political corruption, criminal elements in the government, wealth gap increase, poverty.
-Early 33rd century; New Humanist Progressive Party is founded by a disaffected naval officer, one Vladimir Vasilyev Kuznetsov, an offshoot of the (then-seen-as-corrupt) Socialist Party; it's popular with the badly-paid, corrupt military and less so the public.
-Late 33rd century; total economic collapse of the republic; government dismissed and a highly unpopular President Harrison is elected; new humanism sees a spike in popularity.
-3300; first real battle of the revolution, a badly-handled riot on the capitol of the republic gets out of hand; new humanist radicals feature prominently and enjoy an increase in prominence and popular support. The rebellion on Elysion is crushed almost immediately, but inspires a fresh wave of insurrections that the government tries to crack down on with increasing brutality and panic.
-3302; New Britain Incident, republican navy called in to bombard the planet's capital after seizure by revolutionaries. One ship turns on the flag vessel and destroys it before being destroyed itself. This event marks the formal beginning of the civil war, with mass mutinies occuring across the navy and revolutionary elements in the military organizing in the republic's rim. The legitimate government pulls back and prepares for war.
-3304; Battle of New Britain. Revolutionary forces attack the symbolically-important world. Outclassed republican forces attempt a deception that succeeds in fooling the inexperienced rebel admiral; his executive officer, an as-of-then unknown member of the New Humanist Progressive Party named Roland Stein, shoots him when he refuses to surrender the helm and leads the rebel forces to their first victory. Hereafter his career is generally hindered, but he is not punished for executing his superior.
-3320; Third Battle of Elysion. Republican forces are defeated, naval assets flee. President Harrison is executed. Coalition of Cooperative Planets established. Stein again makes himself known by being a prominent face in relief efforts when the rebels in general are believed to be uselessly bickering.
-3321; Stein's popularity sees him win the chair of the CCP's ruling council. He is now the single-most powerful person in the New Humanist Progressive Party.
-3325; Anya Paterson, a council member and the only credible threat to Stein's popularity, is assassinated by terrorists. Stein reelected due to popularity, a sympathy vote (he was believed to be romantically involved with Paterson). Stein proposes and succeeds in a vote to abolish the council and leave only the Coordinator's position, that is, his.
-3331; Pre-election attempt on Stein's life. It fails. Stein proposes his position be made permanent under the current emergency. He succeeds.
-3334; old Federal Legislature dismissed, new one convened (largely new humanist). CCP is renamed the Humanist Union (not, actually, a reference to new humanism).
-3334-3400; rebuilding, rearming, stabilization, purges, et cetera. During this time frame, the Union annexed the New Haven sector. Relative economic prosperity, even in the rim.
-3400+; Economic recession begins. Increased interest in spreading the Union to other "benighted worlds." Federal government seeks to reestablish formal relations with the outside world.
That was...a bit longer than I'd intended, sorry, but I think it hits on all the important enough stuff. If you (or anyone else) want to read about it in more depth re: future RP scenarios:
http://worldsofsdn.wikia.com/wiki/Histo ... nist_Union .
Hope that helps.