It firtsly Appear on First Gundam Series, "Mobile Suit Gundam". Earth Federation appears in further Series that is on UC era. Earth Federation, is the Main Protagonist on 'Mobile Suit Gundam' and Later became Antagonist on 'Mobile Suit Zeta Gundam' And became Innocent side on 'Mobile Suit Double Zeta Gundam' and later, it became Protagonist and ever.
Earth Federation on 'Mobile Suit Gundam' Refers to Earth Federation Space Forces. Earth Federation Job is to protect the Humanity, and let the Humans to live on Earth. In that Time, Colony has built. And in Zeon 'eyes' that Earth Federation is a fool, why would they let humans to live on earth, which means it may be broke the Earth beauty.
Gundam
0079 EFSF vs ZEON
Earth Federation once didn't felt anything when they knows the Zeons. But Since The Zeon were Felt obligated on Earth Federations Existence. Then, The 'Mobile Suit gundam' Started by 'One Week War' Then to the 'One Year War'. But in 'Mobile Suit Gundam' they only made the scene of 'One year war'. Because its near the Climax.
Because Zeon Fights on the Space, Earth Federation made a Division, Earth Federation, and Earth Federation Space Forces (EFSF). Both means Same, but Earth Federation is more like The Heart and Head. and the EFSF is their Fists and Kicks.
On The Left, This is Their Logo. Earth Federation Heart Is Jaburo, Their Head is Jaburo Too. But Their Skin is on Dakar
Earth Federation first main army were only tanks and Jet planes, until Zeon made a Mobile Suit which it is Zaku i (firstly Mobile Suit Human Body Morph), they began searching meaning of mobile suit. Then they capture one of it, and study it. And then, they made the 'V' Project on side 7. That is the Famous GUNDAM (RX-78) and (RX-78-2)
'V' Project contains
- Gundam (Battlearmed Mobile Suit with Human Body Morph)
- GunCannon (designed as Gundam Aide on a Human Body Morph)
- GunTank (designed as Gundam Aide on a Human-top-Tank Morph)
in other side, there's a Mobile suit that Build for Earth Federation Main Forces, which it is GMs. A Mass Produced Mobile Suit armed on a Beam rifle, Beam saber, and the Shield.
Their last battle on 0079, was an Operation. Called Operation Maelstorm
Maelstorm is to take over A Baoa Qu, but Many Battleships didn't make it to a Baoa qu because of the Colony Laser, Bigzam Beam Laser Canon, and the enemy ships.
Whitebase (or Trojan Horse) is their Finest Battleship that survived until Operation Maelstorm ended Suceed. But in exchange of Whitebase.
the Crews able to Escape, thanks to Amuro (pilot of the Gundam) that has a Newtype potential, he knows that A Baoa Qu will Exploded.
Zeta Gundam
0087 A.E.U.G. Vs Titans (Earth Federation) Vs Axis (later)
Seven Years Passed, Earth federation is like a tree, grown branches. Some of the Branches is Titans. 7 Years Victory because of the Gundam, Titans Made Gundam Mk. ii .But The Titans didn't have pilots that have Newtype potential. And The Titans are mean. So one of the civilians, 'Kamille Bidan' who was a teen that had a Newtype potential, stole the Mark ii and then he joins the AEUG.
Captain Bright Noa, who was the Survivor from One year War (Mobile Suit Gundam) as the White Base Captain, reveals the Titans Horrible and Brutal Tactics, so He later Joins The AEUG alongside 'Emma Sheen'. The Trust able Ensign to Bask Om, she joins AEUG because Titans Execute Kamille's Mother in exchange of Mark ii.
The Battle Went Well, While the AEUG hadn't a chairman, Titans do a tricky things.

One of the Jupitris Person 'Paptimus Scirocco' who had Newtype and Charisma Potential that much, taking over the Titans.
Ironicaly that the Titans is trying to take over the Earth Federation, and then Paptimus Scirocco tried to Take over Titans, and also AXIS (the later of Zeon) had about to Rise.
Scirocco may Intellect, but behind the face, he is a fox and mere brutal.
Because of the Struggle, Titans Lost. But the Earth Federation still survived, in bad condition.