Final answer:
The first victory of Shays' Rebellion was the siege of Northampton, where Daniel Shays and his men took over the Court of Common Pleas to prevent trials of indebted farmers.
Step-by-step explanation:
The first victory of Shays' Rebellion was the siege of Northampton. In the fall of 1786, Daniel Shays, a Revolutionary War veteran, led a group of heavily indebted farmers in an insurrection against the Massachusetts state government. Their actions were driven by grievances including unfair taxation, a shortage of cash money, and high legal fees. Shays and his followers managed to take over the Court of Common Pleas in Northampton, an action that initially marked a victory for the rebels in their attempt to prevent trials and foreclosures affecting indebted farmers. However, this uprising was ultimately suppressed by troops raised by the Massachusetts Governor with the backing of bankers and merchants.