Following the horrors of the Reunification War, the so-called Good Years (2601-2650) saw the Star League deliver upon the peace and prosperity its formation promised. Under the rein of First Lord Nicholas Cameron, the period saw great technological advances and massive economic and trade increases which benefited all members of the League.
Freed from the demands of weapons research and a war economy, the leaders of Star League member states could direct their scientific and industrial resources toward creating a better life for all. Perhaps the most significant technological development during Nicholas Cameron’s reign was the Hyperpulse Generator, developed from technology based on Kearny-Fuchida hyperdrive principles. Essentially a large "gun" that fired a high-frequency compressed data pulse through K-F space at a target world. The pulse traveled the immense distance instantaneously, just like a faster-than-light spacecraft. Though the energy cost of a single transmission was of the same magnitude as for a jump by an FTL ship, an HPG pulse could travel up to 50 light years, while a ship could jump a maximum of 30 light years. When research was completed in 2620, the system effectively cut the average communication time between Terra and the Periphery from more than a year to about six months. Communications time could be cut to days, but only at great cost.    
In 2622, League engineers at the Caph Institute of Technology developed the Jamerson-Ulikov Water Purification Procedure, half the size a third the cost of any previous water-purification system. It was significantly cheaper to operate this J-U Water Purifer than to import water, making it economically feasible to settle Inner Sphere worlds previously ignored during the Exodus. The system also provided many settled worlds with an unexpected economic boom. The Ryan Cartel, the great iceship manufacturer and operator, was nearly driven bankrupt as fewer and fewer worlds relied on its service. Between the period from 2632 to 2700, more than a thousand new worlds had been settled, and the Star League had expanded to control a sphere roughly 540 light years in diameter.    
In a final important development, engineers working to improve BattleMech mobility were able to develop an improved, more efficient myomer. This improvement finally made it possible to construct artificial "bionic" limbs of human size, as well as full-scale, super-string human exoskeletons for use in industry.  
Trade and Economic Expansion
Though a minor economic depression affected every government immediately following the Reunification War, the Inner Sphere began to boom as corporations retooled their factories to produce civilian rather than military items. Trade with the new Territorial states was especially profitable because they lacked almost everything and were willing to pay with vital raw resources from their worlds. Once again, it was cargoships laden with goods rather SLDF troopships making their way among the worlds of the Periphery.    
Another major change that First Lord Nicholas instituted was the unification of the entire Star League under one economic system, based around the Star League Dollar. When he announced his ambitious plans in 2621, reactions were mixed, with the Kurita and Steiner governments most notably opposed because they feared becoming too dependent economically on the other states of the Inner Sphere and concerned it seemed to violate the sovereignty of an individual realm. The major corporations in all the member-states approved of the First Lord's economic plan, businessmen saw a single currency as a way to raise profits and to simplify the maddeningly complicated monetary exchange system that hampered all their dealings and their protests ensured it's universal adoption, officially bugan on July 1, 2623. As the First Lord had foreseen, the new economic system led to an unparalleled boom in trade. Merchants traveled to the farthest corners of occupied space, bringing prosperity and a better quality of life to all.   
The Good Years End
Despite hopes that the good times would continue forever more, in 2650 reports reached Terra that Tadeo Amaris, leader of the Rim Worlds Territorial-State, was expanding his personal army at an alarming rate. Michael Cameron, having recently succeeded to the title of First Lord of the Star League, convened a special meeting of the Star League High Council, whom he persuaded to issue the Council Edict of 2650 restricting the size of personal military forces that any League member could raise. To back up this administrative action, Cameron gave Amaris a warning by sending several Star League Defense Force BattleMech regiments to conduct extended maneuvers just beyond the boundary of the Rim Worlds. Shortly after, League intelligence confirmed that Amaris had apparently disbanded his extra regiments.  
In truth, Amaris and other state leaders continued in secret to strengthen their militia and reserves. While the relative peace and prosperity continued for another hundred years, an increasing discontent set in and "minor" conflicts such as the First and Second Hidden Wars, and the War of Davion Succession began to occur more frequently.  
While this golden age was applauded by all member states of the League, it also sowed the seeds of its eventual collapse. As prosperity of the period grew, Star League worlds became increasingly interdependent. With development and transportation costs low, many planets developed highly specialized economies that made them dependent on other worlds for basic commodities such as food, water-purification equipment, and replacement parts. While this presented no problem during this optimistic era, the collapse of Star League sounded the death-knell for goodwill and free trade which allowed them to survive. 
- The Star League, pp. 54-55 "Economic and Scientific Advances"
- MechWarrior 1st Edition, p. 6 "A History of Human Space, 2001-3025 - The Good Years (2601-2750)"
- MechWarrior 2nd Edition, pp. 109-11 "Historical Overview - The Good Years (2601-2750)"
- Historical: Reunification Wars, pp. 165-166 "Aftermath - Good Years - The Second Invasion"