James married Annette Emilie Eliza Margethe Krøyer Abt 1879, Danmark. Annette (daughter of Henrik Adolph Krøyer and Annathea Hedvig Caroline de Klauman) was born 29 May 1858, of København, Danmark; died 4 Jul 1946, of København, Danmark. [Group Sheet]

1. Johan Adolph Maag was born 8 Jun 1880, Danmark; was christened 8 Aug 1880; died 23 Jul 1965.
2. Louis Maag was born 22 Jan 1886, Danmark; died 24 Dec 1978.
3. Margrethe Sophie Annathea Maag was born 15 Jun 1887, Danmark; died 16 May 1968.