I was looking at the Boston Public Library's Flickr account and came across some of these old circus pictures. It looks like it used to be quite an event in the city. Here's a selection of some of the pictures.
1928 – Elephants walking into Boston
1930 – Indians riding into Boston for a show
Between 1917 and 1934
Between 1917-1934 – I believe this is on Arlington Street in the Back Bay
Between 1917-1934 – This is Gately Square on the corner of Mass. Ave and Huntington
Between 1933 and 1935 – Camels unloading at Boston Garden
1930 – The training arriving in Boston and being unloaded
Between 1917 and 1934 – Elephants taking a break in the salt water of the Mystic River in Everett
Between 1917 and 1934
Between 1917 – 1934
Between 1940 and 1949 – The elephants arrive at Boston Garden
Some things don't change
2010 – And here's the elephants heading into Boston Garden. From Bill Ilott on Flickr
2005 – Here's what it looks like in more recent times. From elwin on Flickr