Esso (aka ExxonMobil) showed up in one of the first sets ever, released in 1955. Bedford, a truck maker, was also represented in the same set (and others from that year). I do not know if there were Bedford sets released before the Esso/Bedford sets, since they were all released in the same year. http://www.bricklink.com/catalogItem.asp?S=1250-2

Esso also shows up on an actual printed brick in this 1958 accessory set: http://www.bricklink.com/catalogItemInv.asp?S=226-1

Esso (aka ExxonMobil) showed up in one of the first sets ever, released in 1955. Bedford, a truck maker, was also represented in the same set (and others from that year). I do not know if there were Bedford sets released before the Esso/Bedford sets, since they were all released in the same year. 
http://www.bricklink.com/catalogItem.asp?S=1250-2

Esso also shows up on an actual printed brick in this 1958 accessory set: 
http://www.bricklink.com/catalogItemInv.asp?S=226-1
Note that 1958 was the start of the current stud-and-tube technology.

Ferguson plastic tractor (1951):
http://aboutus.lego.com/en-us/lego-group/the_lego_history/1950

Esso (aka ExxonMobil) showed up in one of the first sets ever, released in 1955. Bedford, a truck maker, was also represented in the same set (and others from that year). I do not know if there were Bedford sets released before the Esso/Bedford sets, since they were all released in the same year.

 http://www.bricklink.com/catalogItem.asp?S=1250-2

Esso (aka ExxonMobil) showed up in one of the first sets ever, released in 1955. Bedford, a truck maker, was also represented in the same set (and others from that year). I do not know if there were Bedford sets released before the Esso/Bedford sets, since they were all released in the same year.  http://www.bricklink.com/catalogItem.asp?S=1250-2

Esso also shows up on an actual printed brick in this 1958 accessory set: http://www.bricklink.com/catalogItemInv.asp?S=226-1