Two very complicated accusations with both short and long answers. Short answers:
Tobacco companies may have done research on this, but there is no evidence that the industry succeeded.
Honestly, I don't know enough about COPD to answer that part, but the link to lung cancer is less certain. In all of the years of research, no study that exposed animals to smoke at the same levels smokers get was able to cause lung cancer, even using animals highly susceptible to getting tumors. Only 10% of smokers even get lung cancer. Is that higher than non-smokers? Yes, but there are other lifestyle factors that can come into play for smokers. They tend to be lower income and thus more likely to have a poor diet, higher alcohol use and blue collar jobs that may expose them to other carcinogens that are linked to lung cancer. For example, unlike tobacco smoke, exposing animals to diesel emissions DID cause lung cancer in animals. Poor people tend to live in urban areas and work jobs with a lot of diesel emissions. How do they compensate for that when they look at people who get lung cancer? Not only that, but other causes for lung cancer have largely been overlooked by medical examiners. If someone died of lung cancer, if they ever smoked they were tagged as a "smoking related death" whereas people who didn't smoke were tagged as "natural causes" or just "cancer." This can greatly skew epidemiological statistics on the rates that smokers get lung cancer vs. non-smokers. And research showing that there isn't a strong link is buried so no one ever sees it. Researchers must tow the ANTZ line or they lose jobs and funding. So, much of the research published on lung cancer and smoking can be debated, as well. (I can give you the names of several books that cast doubt on the "strong" link between smoking and lung cancer. Some argue that if you account for errors in data, other factors in lifestyles, genetics and unethical studies created by ANTZ, the rates of lung cancer in smokers isn't really higher than in non-smokers.)
So, how could the tobacco companies "know" smoking contributes to lung cancer before the rest of us when there is still debate today? (OK, that was a long "short" answer, lol!)