Post suffered a mental breakdown in November 1885, the result of the stress and overwork which accompanied his job as a farm implement manufacturer.
Post made a break with his previous life, moving to Texas in 1886, where he came into association with a group of real estate developers in Fort Worth, who were attempting to establish a new community on the eastern outskirts of a town called Riverside.
In 1888, Post began a real estate development of his own in Fort Worth on 200 acres (81 ha) that he had obtained, platting the land for streets and homes and constructing two mills.

The stress of this work again proved too much for Post's constitution, and a second breakdown followed in 1891.
Post began a period of extensive travels in search of a cure, coming to take particular interest in the chemistry of digestion.
After a period traversing Europe, Post visited the Battle Creek Sanitarium of Battle Creek, Michigan, a facility operated by John Harvey Kellogg (brother of Kellogg Company founder Will Keith Kellogg).
Post has been accused of stealing several of Kellogg's recipes, including Kellogg's Caramel Coffee Cereal (Post's Postum), Cornflakes (Toasties), and Malted Nuts (Grape Nuts).

In 1895, Post founded Postum Cereal Co., with his first product, Postum cereal beverage.
 Post's first breakfast cereal premiered in 1897, and he named the product Grape-Nuts cereal because of the fruity aroma noticed during the manufacturing process and the nutty crunch of the finished product.
In 1904, he followed up the Grape Nuts label with a brand of corn flakes, which was first called Elijah's Manna before being renamed Post Toasties in 1908.
The British government refused to allow Post to market his cereal in the United Kingdom using the name Elijah's Manna, stating that it was sacrilegious.

In 1906, Post invested some of his substantial earnings from his food products manufacturing into Texas real estate, purchasing a massive 225,000-acre (91,000 ha) tract in Garza and Lynn Counties.
Post platted a new town, which he called Post City.
Shade trees were planted, farm parcels laid out, and a hotel, school, churches, and a department store were constructed for the new Garza County seat.

In 1907 Collier's Weekly published an article questioning the claim made in advertisements for Grape Nuts that it could cure appendicitis.
Post responded with advertisements questioning the mental capacity of the article's author, and Collier's Weekly sued for libel.
The case was heard in 1910, and Post was fined $50,000.
The decision was overturned on appeal, but advertisements for Postum products stopped making such claims.

Post was a staunch opponent of the trade union movement and was remembered by the National Association of Manufacturers as one who "opposed bitterly boycotts, strikes, lockouts, picketing and other forms of coercion in the relations between employer and employee."
Post was also a leading public advocate of the open shop system.
Post suffered a mental breakdown in November 1885, the result of the stress and overwork which accompanied his job as a farm implement manufacturer. Post made a break with his previous life, moving to Texas in 1886, where he came into association with a group of real estate developers in Fort Worth, who were attempting to establish a new community on the eastern outskirts of a town called Riverside. In 1888, Post began a real estate development of his own in Fort Worth on 200 acres (81 ha) that he had obtained, platting the land for streets and homes and constructing two mills.
The stress of this work again proved too much for Post's constitution, and a second breakdown followed in 1891. Post began a period of extensive travels in search of a cure, coming to take particular interest in the chemistry of digestion. After a period traversing Europe, Post visited the Battle Creek Sanitarium of Battle Creek, Michigan, a facility operated by John Harvey Kellogg (brother of Kellogg Company founder Will Keith Kellogg). Post has been accused of stealing several of Kellogg's recipes, including Kellogg's Caramel Coffee Cereal (Post's Postum), Cornflakes (Toasties), and Malted Nuts (Grape Nuts).
In 1895, Post founded Postum Cereal Co., with his first product, Postum cereal beverage.  Post's first breakfast cereal premiered in 1897, and he named the product Grape-Nuts cereal because of the fruity aroma noticed during the manufacturing process and the nutty crunch of the finished product. In 1904, he followed up the Grape Nuts label with a brand of corn flakes, which was first called Elijah's Manna before being renamed Post Toasties in 1908. The British government refused to allow Post to market his cereal in the United Kingdom using the name Elijah's Manna, stating that it was sacrilegious.
In 1906, Post invested some of his substantial earnings from his food products manufacturing into Texas real estate, purchasing a massive 225,000-acre (91,000 ha) tract in Garza and Lynn Counties. Post platted a new town, which he called Post City. Shade trees were planted, farm parcels laid out, and a hotel, school, churches, and a department store were constructed for the new Garza County seat.
In 1907 Collier's Weekly published an article questioning the claim made in advertisements for Grape Nuts that it could cure appendicitis. Post responded with advertisements questioning the mental capacity of the article's author, and Collier's Weekly sued for libel. The case was heard in 1910, and Post was fined $50,000. The decision was overturned on appeal, but advertisements for Postum products stopped making such claims.
Post was a staunch opponent of the trade union movement and was remembered by the National Association of Manufacturers as one who "opposed bitterly boycotts, strikes, lockouts, picketing and other forms of coercion in the relations between employer and employee." Post was also a leading public advocate of the open shop system.
C. W. Post