kassy

8 years served for drugs sounds serious. Maybe waiver might work, US is generally very unforgiving on drugs crimes, especially trafficking.

While you  believe these crimes happened 'way back', the United States government does not think they happened 'way back'.
 
That is what missileman is saying.
 
Good luck. 

Well, sounds like drugs trafficking? Doesn't matter how long ago was it.
Looks like they will need a waiver.
 

What was the crime for and what did he get convicted of? 

Generally, he cannot get a Greencard if the criminal conviction was for one of the following: 
aggravated felonies (Murder, Drug trafficking, Filing a false tax return, Sexual abuse of a minor (this includes, for example, consensual sex between a 21-year-old and a 17 year-old)) crimes involving “moral turpitude” (Murder, Rape, Fraud, Animal abuse or fighting) crimes involving illegal drugs However, sometimes it is possible to get a waiver of inadmissibility if one can show that their admission to the US would not endanger anyone, and that the U.S. citizen or green card holder spouse would experience “extreme hardship” if the applicant is not allowed to live in the United States.

Depends on the crime.

Two unanswered duplicate posts have been removed from other forums.  Please post a single topic just once, and await answers.  

Everything is moving forward normally. This is what happens where a K2 will get their visa before the K1. Your Visa will come shortly behind your daughters. Nothing to worry about.