ALEXANDRIA, Va. (Reuters)—President Barack Obama on Tuesday signed into law a package of final changes to his landmark overhaul of the U.S. health care system, hailing it as an “important milestone” for reform.

“It represents a major step forward,” President Obama told a college audience in Virginia, just outside Washington, after lawmakers last week put the finishing touches on health care legislation, including reforms in college student loan programs.

The signing capped a yearlong political struggle between Democrats and opposition Republicans that has set the stage for a bitter campaign for control of Congress in November.