News flash, Congress finally passes a law to make Lynching illegal and Emitt Till is still dead, from Yahoo News:

Sixty-five years after 14-year-old Emmett Till was lynched in Mississippi, Congress has approved legislation designating lynching as a hate crime under federal law.

The bill, introduced by Illinois Rep. Bobby Rush and named after Till, comes 120 years after Congress first considered anti-lynching legislation and after dozens of similar efforts were defeated[.…]

Congress has failed to pass anti-lynching legislation nearly 200 times, starting with a bill introduced in 1900 by North Carolina Rep. George Henry White, the only black member of Congress at the time.

Background:

According to the Tuskegee Institute, 4,743 people were lynched between 1882 and 1968 in the United States, including 3,446 African Americans and 1,297 whites. More than 73 percent of lynchings in the post-Civil War period occurred in the Southern states.[9] According to the Equal Justice Initiative, 4,084 African-Americans were lynched between 1877 and 1950 in the South.

It does not take a professional historian, just somebody smarter than a professional politician, to notice that Lynching, as bad as it was, is largely a problem in our rear view mirror.  To go from a problem to a non-problem something changed, and that change did not emanate from Congress.;

The probable cost of a crime is not merely the statutes on the book, but rather the combination of the statutes and the expectation of enforcement
For example, while it is illegal in leek classified information, the unwillingness of the administration to actually enforce the law leaves them powerless to stem the Schiff flow of classified information.

In my perception what changed was the perception of local juries.  Lynching stops when local juries were perceived as no longer being willing to turn a blind eye to murder. If Congress was trying keep Lynching active, they certainly failedl So Representative Rush and ilk, are trying to take a victory lap for a war that was fought and won despite their meager efforts and certainly not because of them.