@Jessica1234,
If I am very interested in someone after a first date, I will usually set up a second date in the next day or two. People make quick impressions after first dates and then scurry on, sometimes without thinking.
I agree with the other posters. If you are interested, you should tell him.
I would respond very positively to a woman who expressed interest. If I had any interest, I would say yes. If I didn't, I would be very gracious and kind (I have certainly been on the other side of this interaction).
In the 21st century, you would think that half of the time it would be the woman who expresses interest... yet it doesn't seem to work that way in the real world.
If you have interest in this man, you should write him to tell him. Say that you enjoyed the date and that you would like to see him again. He might politely decline, or you might go out again and end up falling madly in love and end up in 50 years with your grandkids on your lap.
Life is for living, who knows what will happen. Just do it.