It’s a 1890's farmhouse.
Jeanne...That's a great question! My house is a 1970s and gets so dusty. People will recommend lots of things and I have tried each one but I still have dust. We keep our air filters fresh, as well our air purifier. I just continue to dust and live with it. I will be watching your question to see if you get any ideas I haven't already heard and try. Good luck!
If you have central heating it might be that your heating ducts need to be cleaned.
Have you tried "wet dusting?" Some places are more dustry than others. Change or clean HVAC filters once a month, wash screens a couple times a year, vacuum in between. I wash my walls once a month, sounds excessive, but I have a house full of pets - so for me, necessary, but you probably could get away with a few times a year.
Where I live it is hot and dusty most of the year, plus I have a houseful of pets, dusting and vacuuming is a way of life for me.