The Civil Rights Act of 1964 is known as far reaching due to the language it was passed with. For example, this law helps to stop workplace discrimination based on sex, religion, color, race, or national origin. These different qualifications make it wide reaching, as before this time laws were usually very specific as to who they applied to.
For example, the 15th amendment states that one cannot be stopped from voting based on race, color, or past servitude. This law was specifically targeted at helping African-Americans.
As you can see, with the Civil Rights Act of 1964, it includes individuals other than those African-Americans who are fighting for civil rights. Along with this, the Civil Rights Act ends segregation in public places. This makes it so that this law applies to all citizens, not just African-Americans.