Government Archives Still Primitive

I was trying to find population figures of St Joseph and Kansas City from the mid-19th century. I wanted to find out of St Joseph ever had more population than Kansas City. I could find the addresses of archives to send snail mail to for paper documents, and I found the locations of micro-film sites I could visit. But I didn't need to pour over original documents or seek out patterns from raw data. I just wanted the summative populatuion for either the cities or the counties.

Question: Why did the first railroad in Kansas, the Atchison and Topeka, connect these two cities? Was a link to Atchison (across the Missouri River from St Joseph) better than a link to Kansas City, Kansas (across the River from Kansas City, Missouri)? Popultion was my original interest. Finally I abandon a Census search and just used keywords "1840, city name, population," and found a census figure for Kansas City, 4418, and a rough figure for St Joseph, 6000. That begs the question, how big was Independence. Another line of searches, on rialroads uncovered that the first railroad was built between St Joseph and Hannibal, and only two years later did a link go out between Kansas City and St Louis. Further, the fact that St Louis was trying to be a hub of local resource collection, rather than a point on a larger network (they didn't want to undermine the riverboat traffic) meant that there was not a route from St Louis to other eastern points until later. Meanwhile the line to Hannibal puts it across the river (more or less) from Quincy, a point on the Chicago, Burlinton & Quincy railroad, later Burlington Northern.

So on the one hand, the Kansas railroad could either link to St Joseph, where a railroad had pushed east in 1847, linking with the line out of Hannibal in 1859, the very year that the Atchison & Topeka was founded. A spur connected the St Joseph & Hannibal link the next year. And this link is certainly complete through Quincy as far as Chicago by 1864, but its unclear whether the Kansas railroaders would have known that the Aurora Branch would get to Quincy (they became Chicago, Burlington & Quicny in 1864). On the other hand, the Kansas railroad could link to Kansas City, would not be connected to the St Louis line moving west until 1865. And would terminate in a city, St Louis, where the city fathers wanted to put their eggs in the riverboats.

So this is almost certainly the reason for the line at Atchison, but it would have been nice to find the population data on-line, rather than getting microfilm locations.