From an excellent summary of the food stamp facts since 1969 in The Wall Street Journal, here:
George W. Bush expanded food stamp eligibility with the egregious 2002 farm bill by adjusting deductions and income tests and encouraging states to find more participants. The Pelosi Congress then rebranded the program in the Food, Conservation, and Energy Act of June 2008 to emphasize nutrition rather than the stigma of receiving handouts. As a result and also thanks to the recession in 2008, food stamp participation rose by 10.9 million across the Bush Presidency.
But Mr. Obama is now outstripping that dubious achievement, and in only three years rather than eight. The 2009 stimulus bill increased maximum benefits and authorized more money for states to administer the program. Some 11.2 million more people have joined the rolls from 2009 through 2011, including 4.4 million last year during what was ostensibly an economic recovery.
46.2 million Americans get food stamps according to the latest data here. Fewer than 5 million received them in 1969.