When did Thomas Edison get married and who too?

Thomas Alva Edison (February 11, 1847 - October 18, 1931) was married twice.

He married Mary Stilwell (September 6, 1855 - August 9, 1884), who was 16 and a former employee at his subsidiary: the News Reporting Telegraph Company, on December 25, 1871. It is said that she was constantly ill. However, this did not prevent her from from having three children, who all survived childhood.

• Marion "Dot" Estelle Edison Oeser - (February 18, 1873 - April 16, 1965) She was married to German Army Lieutenant Karl Oscar Oeser from October 1, 1895 - 1921.
• Thomas "Dash" Alva Edison, Jr. - (January 10, 1876 - August 25, 1935) He was married twice. First, secretly, to Marie Louise Toohey, a stage actress on February 19, 1899; they would divorce after just eighteen months. Secondly, to Beatrice Heyzer on July 7, 1906, which would last until his death.
• William Leslie Edison - (October 26, 1878 - August 10, 1937) He married Blanche Travers on November 7, 1899.1

Edison loved his wife deeply; but sadly, she would pass away at the young age of 29 on August 9, 1884, possibly of a brain tumor or an overdose of morphine.2

They had been married only 13 years.

Two years later, when Thomas Edison was 39, he married a second time to Mina (pronounced MI-na) Miller Edison(July 6, 1865 - August 24, 1947) on February 24, 1886. She was 20 years old.

The daughter of an inventor, she was the perfect match for Edison: managing everything from the new home to three stepchildren from Edison's previous marriage. He even nicknamed her "Billie". She was member of an extensive amount of charitable organizations.

During their marriage, which lasted until his death in 1931, Thomas and Mina Miller Edison also had three children of their own:

• Madeleine "Toots" Edison Sloane - (May 31, 1888 - February 14, 1979) She married John Eyre Sloane (September 16, 1886 - July 17, 1970) an airplane manufacturer on June 17, 1914. They would have four sons together, which would be the only grandchildren Thomas Edison would have from either marriage.
• Charles Edison - (August 3, 1890 - July 31, 1969) He was appointed by President Roosevelt first as Assistant Secretary of the Navy, then as Acting Secretary; resigning only to run and become Governor of New Jersey from 1941 - 1944. He married Carolyn "Pony" Hawkins two years after they met on March 27, 1918
• Theodore Miller "Ted" Edison - (July 10, 1898 - November 25, 1992) Himself also an inventor with over 80 patents; he married Anna Maria "Ann" Osterhouton May 4, 1925.

After Thomas Edison's death, Mina married Edward Everett Hughes (March 14, 1862 - January 19, 1940), her childhood sweetheart and lawyer, the son of a well-to-do Pennsylvania family, on August 30, 1935. They lived at Glenmont in New Jersey (the house Thomas Edison had bought as a wedding gift to Mina, but had transferred into her ownership to protect the house from being sold, in case Edison went bankrupt) until Hughes death in 1940, after which she again took the name of Mrs. Edison.

She would remain at Glenmont until her death in 1947. She was 82 years old.

Note: 1Because none of Thomas and Mary Stilwell Edison's children had any issue, they have no living direct descendants.

2Mrs. Stilwell Edison's death certificate states that she died of "congestion of the brain". However, if, as some believe, she died of a morphine overdose (which is quite plausible), it would not be, most likely, because of a drug addiction; but, because morphine was a common prescription in the 19th century for many different diseases and it was quite easy to make an unintentional mistake.

See sources for more detail.