In 1942, the Supreme Court ruled in Wickard v. Filburn that the Commerce Clause gives the United States federal government authority to regulate wheat production, even if that production is for personal consumption. How did this affect future Court decisions, and what are some major acts of Congress that depend on this ruling?
It basically gave Congress permission to regulate anything. It stretched the commerce clause to cover anything with even a vague downstream effect on actual or potential interstate commerce. Some would contend that it essentially made the 9th and 10th amendments obsolete, but a rare ruling in 1990, United States v. Lopez struck down the Gun-Free School Zones Act of 1990. There was also the Printz v. United States case that struck down another gun control law on tenth amendment grounds.
Having received the signal that the courts would seldom object to any overreach, congress basically was able to assume the mission of state legislators in addition to their existing role. This would include things like health care, labor, education, and other things that were previously off-limits.
The structure of the USA is legally that of a federation with the federal government and the states jointly sharing sovereignty (with ultimate legitimacy derived from the consent of those governed). The Supremacy Clause definitely gives the federal government the upper hand, but this was supposed to be limited to a narrow list of powers. With this restriction removed, one might argue that the USA is effectively becoming a de-facto unitary state, but it isn't one yet due to a few remaining commerce clause restrictions and things like the anti-commandeering doctrine.