Spurgeon sermons are some of the most beloved and widely circulated classic sermons. Many of them are available online (see below).
Charles Haddon Spurgeon was born in 1834 and died in 1892. He was known as the Prince of Preachers. During his ministry it is estimated that Spurgeon preached to as many as 10 million people and at times preached up to 10 sermons each week.
As pastor of New Park Street Chapel in London, Spurgeon became the most popular preacher of his era. Spurgeon's sermons were printed each week and distributed to many.
The congregation soon outgrew the chapel and eventually ended up in the Metropolitan Tabernacle. His congregation was perhaps the first "mega-church." He often preached to more than 10,000 people.
Spurgeon was almost certainly suffering from depression during some of his ministry. He admitted that at times he cried for no reason. This was not just a temporary problem. Spurgeon struggled with apparent clinical depression for a number of years.
By the time of his death, he had preached more than 3,600 sermons - most of which were published. He also wrote commentaries, illustrations, hymns, and devotions.
There are several sources on the web for the sermons of Charles Spurgeon. The following list will get you started.