Hubkittel on the Browns Forum wrote:
The browns had a higher attendance than the cardinals in 17 of their first 25 seasons. Their 26th season was in 1926 (and we all know what happened that year). After 1925, the only year the browns outdrew the cards was in 1944 and they only outdrew them by 53,000.
While the great depression was tough on everybody (a fantastic understatement), it really hit the browns hard. After 1929, the browns wouldn't draw more than 179,000 fans in a season until 1940.
The years 1944-46 are fairly interesting. the browns drew reasonably well by their standards and by the standards of St. Louis baseball. They drew 509,000 in 44, 483,000 in 45, and 526,000 in 46. Their 46 attendance figure was the eleventh highest attendance number in 20th century st. louis baseball history up to that time. It was a darn good year for them. But the cardinals outdrew them by over 500,000.
The browns just got buried in the post war period. starting in 1946, the cards drew over a million fans for six straight years and never drew less than 880,000 between 1946 and 1953. The cards attendance nearly doubled between 45 and 46 while the browns were unable to make a similiar leap. The browns average attendance from 46 to 53 was around 400,000. While that kind of attendance would have been decent in the 20's or 30's, it killed the browns in the post war period.
To answer the question of "Did the browns have a fan base?" i would say it's obvious that they had one. Based on attendance figures, they were the most popular baseball team in st. louis for the first 25 years of their existance. The success of the cardinals after 1925, combined with the great depression, severely hurt the size of the fan base. But the fans came back in the 1940's to the point that 1946 saw the browns drawing more fans then they had in 20 years. The browns were simply unable to expand that fan base in the post war period and that failure killed them in St. Louis.