Final answer:
The passage of the more effective Fugitive Slave Act was met with controversy in the United States.
Step-by-step explanation:
The legislative action that was met with controversy in the United States was A) The passage of a more effective Fugitive Slave Act.
The Fugitive Slave Act of 1850 was a part of the Compromise of 1850, which aimed to settle the sectional tensions between the North and the South over the expansion of slavery in the newly acquired western territories. The act required that escaped slaves be returned to their owners, even if they were in free states, and imposed severe penalties on anyone who aided or harbored fugitive slaves.
This controversial law sparked outrage in the North and contributed to the growing divide between the North and the South leading up to the Civil War.